You've spent the last 45 minutes trying to get ChatGPT to sound more like you.
"Make it more conversational."
"Less corporate."
"Add a bit of personality."
"FFS, I WOULD NEVER SAY THAT."
Six rewrites later, you're looking at a piece of content that still sounds like it could have come from literally anyone in your industry.
The good news is that you absolutely CAN customise ChatGPT and Claude to produce content that sounds like you.
But, it's going to require you to do some actual thinking first. I know. Disgusting.
After spending 10 years writing content for different businesses, and now using AI as part of that process every single day, I've learned that the quality of what comes out is largely determined by what goes in.
And there's one mistake I see people making ALL the time.
We'll get to that in a minute.
How do you make ChatGPT or Claude sound like your brand?
To customise ChatGPT or Claude to sound like your brand, set up a Project for your business and fill it with brand documents in your own words: your opinions, your clients, your offers and real examples of your writing. Then add short instructions telling it how to use them.
Stop expecting a clever prompt to do the job of a proper brand foundation.
What you actually need is a dedicated Project containing information about your business, your clients, your offers, your opinions and the way you genuinely communicate.
Both ChatGPT and Claude let you create Projects with their own instructions and reference documents.
I have a separate Project for every client in both tools.
Inside each one, there's everything the AI needs to understand who it's writing for, what the business believes and how that particular person communicates.
Then, when I ask it to write something, I'm not starting from scratch or trying to explain the entire business in one ridiculously long prompt.
Those documents need to contain your ACTUAL thoughts and words. Not a collection of lovely-sounding adjectives ChatGPT came up with on your behalf. Which brings me to my biggest bugbear.
The biggest mistake people make when customising AI
Right. This drives me a bit mad.
People open ChatGPT and ask it to create their brand voice guide. Then their ideal client profile. Then their brand story. Then their messaging pillars.
Lovely. Look at us being all organised.
They upload everything into a Project, tell ChatGPT to use those documents and sit back expecting content that sounds EXACTLY like them.
Except it doesn't. It sounds like AI. SHOCKING.
You've essentially asked AI to make up your brand personality, then asked it to imitate the personality it just made up. And this is how we end up with 4,000 businesses whose brand voice is described as: "Warm, approachable, professional and authentic." Groundbreaking stuff.
You cannot expect AI to capture a personality you haven't given it.
And I think this is where a lot of people misunderstand what makes good AI-generated content.
There's no magical prompt that makes ChatGPT more human. You have to give it something HUMAN to work with.
AI can help you organise all that. It can help you write it, structure it and turn it into content. But I wouldn't let it decide what your business thinks in the first place. Which brings me to something I do that I genuinely think makes a massive difference.
Why I talk to AI instead of typing
A little while ago, I signed up for a free trial of a dictation tool called Wispr Flow. And when I say I signed up for a free trial, what I actually mean is I fully intended to use it for a week, decide it was another unnecessary subscription and cancel before they charged me.
Well. That didn't quite go to plan. I barely type anymore. Even when I'm editing client blogs, I'll read a paragraph and dictate the changes I want rather than typing them.
And before anyone asks, no, this isn't some big sponsored love letter to Wispr Flow. I just genuinely love the thing. Although I do have an affiliate link that gets you a free month if you fancy trying it.
Anyway. Here's why I think dictation has made such a difference to the content I create with AI.
You write differently from how you speak
Think about how you'd explain your business to someone over a drink. You'd probably tell them a story. Go off on a tangent. Say something slightly inappropriate. Remember a brilliant example halfway through explaining something else. And you'd use words and phrases that come completely naturally to you.
Now imagine sitting down and trying to type all of that into a formal brand document. Suddenly, you're editing yourself. Tidying up the sentences. And before you know it, you've taken all the personality out of the very document that's supposed to capture it.
When I dictate, AI gets my actual words. Not the heavily edited version of me that occasionally appears when I start treating a Google Doc like a job application.
It gets my phrasing, my examples, the way I explain things and the opinions I probably wouldn't bother typing out in full.
Your brand voice isn't just whether you swear or use short sentences. It's the way you see things. A voice guide can tell AI that you're blunt, funny and conversational. But it can't magically invent the observation you'd make after ten years working with clients. That's the good stuff.
And that's exactly what I want going into my AI Projects.
How to use dictation to create better brand documents
You don't need Wispr Flow, by the way. Your phone's voice-to-text function, a voice recording you transcribe, or the microphone tools available in ChatGPT and Claude can all help.
The important thing is getting your thoughts out without editing every sentence halfway through.
Here's what I'd suggest. Open a document or voice recorder. Pretend I'm sitting opposite you with a glass of wine, asking questions about your business. And actually ANSWER them. Not in the way you think you're supposed to answer them. The way you'd explain it to me.
Try these:
Who's your favourite type of client to work with, and what makes them different?
What advice in your industry makes you want to roll your eyes?
What do clients consistently misunderstand before they work with you?
What's something you believe that other people in your industry might disagree with?
How would you explain your main offer to someone who's never heard of your business?
What stories or experiences have shaped the way you work?
Don't worry about sounding polished. In fact, I'd actively avoid it. Get the messy thoughts out first. Then give the transcript to ChatGPT or Claude and ask it to organise everything into useful documents.
But here's the important instruction: preserve my actual opinions, examples and language. Don't rewrite everything to sound more professional.
Because otherwise we're right back where we started. Feeding AI with AI. And I've already told you how I feel about that.
How I set up ChatGPT and Claude Projects for my clients
Right, let's get into the practical stuff.
I work across multiple brands, so keeping everything separate is pretty important. Nobody wants their corporate accountancy client suddenly sounding like a sweary northern marketing agency. Although I'd quite enjoy reading that.
Every client gets their own Project in ChatGPT and Claude, with their own information, writing examples and instructions.
If you're only creating content for your own business, you can just start with one.
In ChatGPT, you'll find the option to create a new Project in the sidebar.
In Claude, head to Projects and create a new one there.
I split the setup into two main parts:
1. Brand documents: What the AI needs to know.
2. Project instructions: How I want it to use that information.
And I put considerably more effort into the first part.
Step 1: Create your brand documents
These are the documents I generally start with.
| Document | What I include |
|---|---|
| Background and story | How the business got started, why it started and who's involved, including team members |
| Founder profile | Who the founder is, their experience and what they're known for. The minimum for any personal brand |
| Team profiles | A short profile for each team member who gets mentioned in content, so AI describes them accurately |
| Brand voice | How the founder naturally speaks, favourite phrases, words they'd never use and examples of their real writing |
| Ideal client | Who they're trying to attract, what those people are struggling with, what they want and how they actually describe their problems |
| Offers | What the business sells, who each service is for, what's included and relevant pricing |
| Writing rules | Things like British English, formatting preferences, words to avoid and recurring AI habits we want to cut |
| Writing examples | Real emails, captions, blogs and other content that capture the founder's voice particularly well |
A quick tip for the brand voice document. When I wrote mine, I asked friends and family which words and phrases I say a lot. They came back with quite a few. Every one of them went into my voice guide. If you want AI to sound like you, ask the people who actually listen to you.
But there's something I'd add to that list. And personally, I think it's one of the most important documents you can create.
Your opinions and beliefs
I've got a whole document dedicated to the things I believe about marketing. The things I refuse to do, the advice I disagree with and the mistakes I see business owners making over and over.
Because most brand voice guides tell AI HOW you speak. They don't tell it WHAT you think.
Tell ChatGPT your voice is "bold, conversational, funny and occasionally sweary" and it'll start chucking the odd F bomb into a perfectly generic marketing tip. Very edgy… NOT!
This blog is a pretty good example of the alternative.
I could have just given you a list of prompts to make AI sound more like you. Plenty of people will. But I don't think that works. That's a strong belief of mine, and not everybody will agree with it. It's also the reason this post looks the way it does.
A tone of voice guide could never have given AI that. The hot sauce is the actual take.
Step 2: Add examples of your actual writing
This is another big one.
You can tell AI how you sound until you're blue in the face. But showing it is usually far more useful. So I upload things like:
Emails the client has written themselves (not with AI).
Social posts that really capture their personality.
Blog posts they're particularly happy with.
Voice note transcripts.
Examples of phrases they naturally use.
And sometimes examples of things they absolutely HATE. Because knowing what you don't sound like is pretty useful too.
Step 3: Give the Project some instructions
Now we've got the documents, we need to tell ChatGPT or Claude what to do with them. And I wouldn't overcomplicate this.
You don't need a 2,000-word prompt telling AI to act as an award-winning accountancy firm with 47 years of experience and a deep passion for spreadsheets.
Please. The Project already has your information. The instructions just need to explain how to use it.
Something along these lines:
“You’re writing content for [BUSINESS NAME].
Use the documents in this Project as your primary reference for the business, audience, offers, brand voice and founder’s opinions.
Follow the writing rules document for every piece of content.
Preserve the founder’s natural language, humour, opinions and examples. Do not replace specific observations with generic marketing advice.
If there isn’t enough information to write something specific or accurate, ask for the missing details instead of inventing them.
Don’t introduce claims, results, stories or opinions that aren’t supported by the information provided.”
And that's pretty much it.
Obviously, you can make these more detailed depending on your business. But I think people get a bit too obsessed with trying to write the perfect set of AI instructions.
A fancy prompt won't rescue shit source material.
I'd rather have five genuinely useful brand documents and simple instructions than the world's most sophisticated prompt attached to a pile of generic waffle.
How I actually use ChatGPT and Claude to write content
Once you've got everything set up, the process becomes considerably easier. But there's still one thing I don't do. I don't just open the Project and type:
"Write me a LinkedIn post about marketing." Because what exactly is it supposed to do with that? It knows the brand now, yes. But it doesn't know what I want to say about marketing TODAY.
Here's roughly how I work.
1. I open the right Project
Pretty self-explanatory.
If I'm working on a client blog, I open their Project so the relevant brand information and instructions are available. No explaining who the client is for the 94th time.
2. I dictate what I actually want to say
I explain the topic, the point I want to make, the angle we're taking and any examples or stories I want included.
Sometimes I'll ramble for five minutes. Sometimes I'll go off on a completely different tangent and end up realising THAT is actually the more interesting angle. Which is why I love dictation. I'm thinking out loud rather than trying to write perfectly structured instructions.
3. I get the structure right before writing
For a bigger piece of content, like a blog, I'll usually ask for an outline first. Because there's absolutely no point writing 2,000 words and then realising the whole thing is going in the wrong direction. I'd rather get the argument and structure right before we start producing paragraphs.
4. I work through the content in sections
I find this gives me more control over the writing. I can see where something's becoming generic, where we need a better example or where the original point is getting lost. And I can correct it before we've got an entire article full of the same problem.
5. I edit by talking
Rather than sitting there rewriting every sentence myself, I'll often dictate what isn't working.
"This doesn't sound like her."
"We've already made this point."
"That's too corporate."
"We need an actual example here."
Or my personal favourite:
"What the fuck does that even mean?"
It's a collaborative process.
The AI does a lot of the heavy lifting, but the thinking, judgment and final decisions are still coming from a person. Which is kind of how I think AI should be used in marketing.
If you want the full process, I've written another article on how I write blog posts with AI.
ChatGPT vs Claude: which is better for writing in your brand voice?
I use both. And I don't think you need to get particularly precious about which one you choose.
Both let you create Projects, upload reference material and provide instructions for how you want content written. And both are capable of producing very generic content if you don't give them anything interesting to work with.
The biggest difference, in my experience, comes from what you feed them and how you direct the work.
A properly set-up ChatGPT Project with real brand information is going to give you a much better starting point than a Claude Project full of AI-generated brand documents. And vice versa.
I've got paid accounts for both, and I use them pretty much interchangeably. If I'm not getting what I want from one, I'll take the same brief over to the other and see if it comes back different. Sometimes it does. Which is another good reason to keep the same brand documents in both.
Pick whichever one (or both if you’re greedy like me) you find easiest to work with. Get your brand documents right and learn how to brief it properly.
And stop jumping between tools every time somebody on LinkedIn announces that the latest model has completely changed their life. Half the time, they just want you to buy their prompt pack.
What if you've already built a custom GPT?
If you've been using a custom GPT for your business, there's an important update.
OpenAI has announced plans to retire custom GPTs, with the standard retirement date currently scheduled for 11 December 2026.
Some workspaces have different dates, so check the notice for your account.
OpenAI is providing a migration route to plugins, but if you mainly used your GPT to store brand instructions and writing reference files, a ChatGPT Project is another option.
For that kind of writing workflow, here's how I'd approach moving things over:
Save the instructions from your existing custom GPT.
Gather the brand documents and examples you've uploaded.
Create a new Project in ChatGPT.
Add the reference documents and your Project instructions.
Test it using a few prompts you've used before.
Compare the output and make adjustments where needed.
And while you're doing all that, have a look at the original brand documents.
Because if you created them by asking ChatGPT to tell you who your business is, now would be a lovely time to revisit them.
Read OpenAI's official custom GPT retirement guidance.
How to stop ChatGPT and Claude slipping back into generic content
It’s worth remembering your brand isn't fixed. Your offers change. You learn more about your clients. You develop stronger opinions. You get better at explaining what you do. And occasionally you look back at something you wrote six months ago and wonder who the hell authorised it. So your brand documents need to evolve with you.
A few things I'd recommend:
Update your offers when something changes.
New service? Different pricing? Changed positioning?
Update the relevant document.
Otherwise, don't be surprised when AI starts writing about a service you stopped offering in February.
Keep adding good writing examples.
When you write an email that feels particularly YOU, add it. When a client publishes a brilliant piece of content, save it. Give the Project more examples of what you actually want.
Save your best opinions and stories.
Had a client conversation that made you realise something? Record it. Found yourself ranting about some terrible industry advice? Lovely. Get that down too.
Those are often the most useful ingredients for future content.
And for the love of God, read what AI gives you before publishing it.
I don't care how good your Project is. AI can still get things wrong. It can still misunderstand your point. And it can still produce something that sounds suspiciously like a motivational speaker at a networking breakfast.
If you wouldn't say it, don't publish it.
And if it's a blog, run it through my 15-step blog SEO checklist before it goes live.
What actually makes AI content sound like you
I think we're getting to a point where almost everybody has access to the same AI tools. Which means simply knowing how to use ChatGPT isn't much of a competitive advantage anymore.
Anybody can ask AI to write a blog. Anybody can generate 30 Instagram captions. Anybody can produce a perfectly acceptable LinkedIn post about the importance of showing up consistently. And my God, do they.
The difference is what YOU give it to work with. That's what makes content worth reading. It's also what gives AI search tools a reason to quote you, which I've covered in SEO vs AI search.
So yes, customise Claude. Set up your ChatGPT Projects. Build your brand documents. Use AI to help you create content faster. But don't outsource the actual thinking. Because if you strip away everything that makes your business different and ask AI to fill in the gaps, it'll happily give you a perfectly polished version of everybody else. And we really don't need any more of those.
Want the content without having to run the entire production process yourself?
That's what we do at Clowt.
We get the opinions, stories and expertise out of your head, turn them into marketing that sounds like you and handle the work of getting it out into the world.
You bring the brain. We do the heavy lifting.
Frequently asked questions
Is there a way to customise Claude?
Yes. Claude has several ways to personalise how it responds, including account-wide instructions, Styles and Projects.
For brand content, I use Projects because they let me keep the relevant instructions and documents together.
That means I can have one setup for Clowt and completely different setups for clients.
Without everybody accidentally inheriting my potty mouth.
How do I customise Claude's writing style?
In Claude, open the style menu, select Create & edit styles, then create a custom style (Anthropic's guide to Styles).
You can provide examples of your own writing or describe the style you want.
I'd recommend using genuine examples rather than asking Claude to invent a brand voice from scratch.
How do I build a custom Claude for my business?
Create a Project in Claude and add your brand documents to its knowledge area.
Then add Project instructions explaining how Claude should use that information.
This gives you a dedicated workspace with reference material specific to your business.
How do I customise ChatGPT's personality?
Go to Settings → Personalization → Base style and tone and choose the personality that suits you.
You can also adjust your general instructions and other personalisation preferences. But I'd make an important distinction here. Changing ChatGPT's personality affects how it communicates with you. It doesn't automatically teach it everything about your business. For brand-specific content, I'd still recommend a dedicated Project with proper reference documents.
What are the best ChatGPT custom instructions for brand writing?
The ones that are actually specific to your business
Tell it who it's writing for, which documents to reference, what rules to follow and what to do if information is missing.
You can put general preferences in your account settings and keep business-specific guidance inside your Project. And please don't rely entirely on instructions like "be engaging and authentic".
What does that even mean? Give it actual examples.
Can AI write my brand voice guide for me?
It can help you organise and structure one. But I wouldn't ask it to invent your brand voice.
Start with real writing, voice notes, opinions, client experiences and examples. Then use AI to organise those into a document without polishing all the personality out of them.
How long should my brand voice documents be?
As long as they need to be useful. I'd take a shorter document full of specific opinions, language and real examples over ten pages of generic brand adjectives any day. Quality over quantity.
Do I need both ChatGPT and Claude?
Nope. I use both because I work across different clients and workflows, but you absolutely don't need two AI subscriptions to create good content.
Pick one, learn how to use it properly and give it decent information. That'll get you further than collecting AI tools like Pokémon.
