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Content Creation Workflows

Brand Voice Guide: Create One With AI (With Examples)

Create a brand voice guide with AI: describe how you sound, set words to use and avoid, and give AI tools rules so every post sounds like you, not a robot.

Time to complete
60 to 90 minutes
Tools needed
ChatGPT, Claude or Gemini (with custom instructions or projects if available)10 to 20 pieces of your own writinga doc

You can spot AI-written content in a second: the same rhythm, the same "In today's fast-paced world", the same three-part lists. Audiences scroll past it, and it makes even good ideas feel cheap. The problem isn't AI. It's that AI doesn't know how you sound, so it falls back on a bland default.

A brand voice guide fixes this. It's a short document that captures how you or your brand speaks: your personality, the words you use, the words you never use and how your tone shifts by platform. Give it to AI and the drafts start sounding like you. Give it to a freelancer or new team member and they can write for you without weeks of edits.

By the end of this workflow, you will have a one-page brand voice guide built from your own writing, a set of before-and-after examples and a ready-to-paste instruction block that makes any AI tool write in your voice.

What a brand voice is

Your brand voice is your consistent personality in writing. Tone is how that voice adjusts to the situation. You might be playful on TikTok and more measured in a client proposal, but it should still sound like the same person.

A useful brand voice guide covers:

  • Three or four voice traits, each with "this, not that" (for example, "confident, not arrogant").

  • Words and phrases you use, including local expressions if they're part of how you talk.

  • Words and phrases you avoid, including common AI clichés.

  • Sentence style: short or long, formal or casual, contractions or not.

  • Tone by channel: how you adjust for LinkedIn, Instagram, email and customer messages.

  • Examples: real before-and-after rewrites.

Keep it to one page. A 20-page guide nobody reads is worse than none.

Before you start

Collect 10 to 20 pieces of writing that sound most like you at your best. Good sources are:

  • your best-performing posts and captions

  • emails or messages to customers that got warm replies

  • a voice note or video transcript where you explain something naturally

  • your website's About page, if you wrote it yourself

Skip anything that someone else wrote or that you edited heavily to sound formal. If you're building a voice for a business, include writing from the founder and anyone customers love dealing with.

Step 1: Analyse your writing

Paste your samples into AI and ask it to describe your voice. Be specific about what you want it to look for.

Here are [number] samples of my writing:
[paste samples, separated by ---]

Analyse my writing voice. Describe:
1. My personality in 4 traits, each as "this, not that"
2. Average sentence length and rhythm
3. Words and phrases I use often
4. How I open and close posts or messages
5. My use of humour, slang, local expressions and emojis
6. Anything that makes my writing distinctive
Quote short examples from my samples for each point.

Checkpoint: you have a description of your voice with quoted examples, and it feels accurate when you read it.

Step 2: Choose your voice traits

AI's analysis is a starting point. Now decide how you want to sound, not just how you've sounded. Edit the traits until they feel right.

Based on this analysis: [paste]
My audience: [audience]
How I want people to feel after reading my content: [feeling]

Suggest a final set of 3 to 4 voice traits.
For each:
- the trait, as "this, not that"
- one sentence explaining what it means in practice
- one example sentence that shows it

Checkpoint: you have three or four traits you'd be happy for a stranger to use to describe you.

Step 3: Build your word lists

Word lists are the most practical part of the guide. They catch problems AI drafts fall into most often.

Using my samples and voice traits, create:
1. 15 words or phrases I use that fit my voice
2. 20 words or phrases I should avoid, including common AI clichés such as "delve", "unlock", "game-changer", "in today's fast-paced world" and "elevate"
3. Rules for punctuation and formatting (for example, emojis, exclamation marks, contractions, British or American spelling)

Add anything you personally dislike seeing. Keep expressions that are part of your identity, such as Pidgin or Yoruba phrases you naturally use with your audience.

Checkpoint: you have a "use" list, an "avoid" list and a short set of formatting rules.

Step 4: Set tone by channel

The same voice flexes for different places. Write one or two lines per channel you use.

My voice traits: [traits]
I publish on: [channels]

For each channel, describe how my tone should adjust in 2 sentences.
Include typical length, formality and one example opening line.

Checkpoint: each channel you use has a short tone note and an example opening line.

Step 5: Test it with before-and-after rewrites

A guide is only useful if it changes the writing. Test it on a generic draft.

Here is my brand voice guide:
[paste guide so far]

Here is a generic draft:
[paste a bland AI draft or old post]

Rewrite the draft in my voice, following every rule in the guide.
Then list which rules you applied and where.

Compare the rewrite with your real writing. If it still doesn't sound like you, adjust the traits or word lists and test again. Keep the best before-and-after pair as an example in your guide.

Checkpoint: a rewrite passes the "would my followers believe I wrote this?" test.

Step 6: Turn it into AI instructions

Finally, condense the guide into an instruction block you can paste into any AI tool, or save in custom instructions or a project.

Turn this brand voice guide into a set of writing instructions for an AI assistant.
Rules:
- Under 250 words
- Written as direct instructions ("Write in short sentences...")
- Include the avoid list in full
- End with: "If a sentence sounds like generic marketing, rewrite it."

[paste guide]

Checkpoint: you have a saved instruction block under 250 words, and drafts written with it need only light edits.

Brand voice examples

Here is how the same message changes with three different brand voices. The message: a new delivery option is available.

  • Warm and neighbourly (a family bakery in Ibadan): "Good news! Your favourite agege bread can now come to your door. Order by 10am, and it'll be with you before lunch."

  • Sharp and practical (a B2B logistics startup): "Same-day delivery is now live in Lagos and Abuja. Book before 11am. Track every parcel in real time."

  • Playful and bold (a streetwear brand): "Your fit, at your door, same day. No stress, no waiting. Lagos, we see you."

Each one is clear, but you'd never mix them up. That's what a brand voice does.

Brand voice guide template

Use this one-page template to lay out your finished guide. Fill each section with what you built in the steps above.

BRAND VOICE GUIDE: [name]

WHO WE'RE TALKING TO
[one sentence about the audience]

OUR VOICE
1. [trait], not [opposite]: [what it means in practice]
2. [trait], not [opposite]: [what it means in practice]
3. [trait], not [opposite]: [what it means in practice]

HOW WE WRITE
- Sentences: [short/medium, contractions yes/no]
- Spelling: [British/American]
- Emojis and exclamation marks: [rule]
- Local expressions: [when and where]

WORDS WE USE
[list]

WORDS WE AVOID
[list, including AI cliches]

TONE BY CHANNEL
- Instagram/TikTok: [note + example opening]
- LinkedIn: [note + example opening]
- Email/WhatsApp: [note + example opening]
- Complaints and support: [note + example opening]

BEFORE AND AFTER
Before: [generic sentence]
After: [same message in our voice]

Share it with anyone who writes for you, and paste the AI instruction block from Step 6 wherever you use AI tools. If you work with a team, keep the guide in a shared doc so everyone uses the latest version.

Worked example

Seun runs a small fitness coaching business and posts on Instagram and WhatsApp. His AI-drafted captions kept coming out sounding like a gym advert: "Unlock your full potential with our transformative programme."

He pasted 15 of his real captions and voice note transcripts into AI. The analysis found he writes short, direct sentences, uses gentle humour and often mentions small wins like "took the stairs today". His final traits were: encouraging, not preachy; direct, not harsh; funny, not silly.

After adding the guide to his AI tool's custom instructions, the same request produced: "You don't need a perfect week. You need three workouts and enough water. Start there." His followers started replying to captions again, and he spends less than five minutes editing each one.

Expected output

You should have:

  • an analysis of your writing with quoted examples

  • three or four voice traits written as "this, not that"

  • "use" and "avoid" word lists and formatting rules

  • tone notes for each channel

  • at least one before-and-after example

  • an AI instruction block under 250 words

Check your work

  • The guide fits on one page.

  • Each trait has a "not that" to set limits.

  • The avoid list includes common AI clichés.

  • Someone who knows you would recognise the voice.

  • A test rewrite sounds like you without heavy editing.

  • The instruction block is saved where you'll actually use it.

Common mistakes

  • Writing traits everyone claims. "Friendly and professional" fits every brand. Add "not that" to make it useful.

  • Building it from someone else's writing. The guide must come from how you or your brand really speak.

  • Making it too long. If it's more than a page, people and AI tools will skip parts.

  • Removing all personality. Local expressions and humour that fit your audience are a strength, not a mistake.

  • Never updating it. Revisit it every few months as your audience and offer change.

  • Trusting AI without checking. Even with a guide, read every draft before you post.

Next step

Use your new voice guide on everything you make in this series: scripts, carousels and newsletters. For more ways to stop content sounding generated, read 10 AI mistakes that make content look AI-generated. To put the guide to work across a whole week of posts, try the turn one idea into a week of content workflow.

FAQ

What is a brand voice?

It's the consistent personality in how a person or brand writes and speaks. It covers word choice, sentence style, humour and attitude.

What's the difference between brand voice and tone?

Voice stays the same everywhere. Tone shifts with the situation, such as more playful on TikTok and more careful when replying to a complaint.

Do small businesses and solo creators need a brand voice guide?

Yes, especially if you use AI tools or work with freelancers. A one-page guide keeps everything sounding like you without constant rewrites.

How do I make AI write in my brand voice?

Give it a short instruction block with your traits, word lists and examples. Save it in custom instructions or a project so you don't paste it every time.

How long should a brand voice guide be?

One page is enough for most creators and small businesses. Larger companies may add more examples, but the core rules should still fit on a page.

Can my brand voice include Pidgin or local expressions?

Yes, if your audience uses and enjoys them. Note in the guide where they fit and where they don't, such as in formal proposals.

More in Content Creation Workflows.