Most brands don't have a voice problem. They have a memory problem. You nail the tone in one email, then three weeks later you're staring at a caption you swear was written by a different, more corporate person who happens to share your name. Sound familiar?
The fix isn't more inspiration. It's a document. A brand voice guide is the single page — okay, maybe two — that tells you, and your AI, and anyone you ever hand the keys to, exactly how your brand talks. Build it once, and you stop reinventing your personality every time you open a blank box.
This is the exact framework I use for every brand in my studio. It's not academic and it's not precious. You can build yours in an afternoon and then use it, quite literally, forever.
First, Why It's Worth the Afternoon
Because consistency is what makes a brand feel like a someone instead of a logo. When your voice is the same across your site, your emails, your captions, and your DMs, people start to trust it before they can even explain why. Familiarity reads as reliability. That's not a trick; it's just how humans work.
And here's the part that matters more every single month: when you use AI to help you write — and you do, or you will — a voice guide is the entire difference between output that sounds like you and output that sounds like a press release from a company that sells nothing. One document. Endless reuse. This is the highest-leverage page you're not writing yet.
Step 1: Define Your Voice Pillars (Three Is Plenty)
Voice pillars are three or four adjectives that describe how your brand sounds. But adjectives on their own are useless, so each one comes with a plain-English "what this means" and "what this doesn't mean." That second column is what makes the whole thing actually usable.
Here's what mine looks like for this brand:
| Pillar | What it means | What it doesn't mean |
|---|---|---|
| Honest | Real numbers, real flops, no fake guru shine | Oversharing, or cynical for sport |
| Warm | Talking to one smart friend who's on your side | Sappy, soft, or scared to have a point |
| Sharp | A little sass, a strong opinion, a good one-liner | Mean, superior, or edgy just to be edgy |
Pick words that are actually yours. "Professional, trustworthy, innovative" describes every brand and therefore no brand. If your three pillars could belong to a bank, a dentist, and a SaaS startup all at once, they're too generic. Go more specific and a little braver.
Step 2: Write Your "We Sound Like / We Never Sound Like"
This is the fastest, most useful section in the whole guide, and it's just two lists. It hands you — and your AI — a razor to check any sentence against.
We sound like:
- A knowledgeable friend who's genuinely rooting for you
- Confident, but never talking down to you
- Plain English with the occasional well-placed joke
- Someone with an actual point of view
We never sound like:
- A LinkedIn "thought leader" clearing his throat
- A terms-and-conditions page
- A hype man with a countdown timer
- A robot that swallowed a thesaurus
Notice the "never" list is doing most of the heavy lifting. It's easy to say "be authentic." It's far more useful to say "do not, under any circumstances, write unlock, leverage, seamless, or in today's fast-paced world." Which brings us to the pettiest, most effective section of all.
Step 3: Build a Word Bank (Words We Use / Words We Ban)
A word bank is a tiny cheat sheet of on-brand and off-brand vocabulary. It sounds fussy. It is also the single thing that most reliably keeps writing in your voice — especially AI-assisted writing, which loves to reach for the exact words you'd never say out loud.
- Words we use: build, real, honest, receipts, actually, chaos, systems, your people, figure it out
- Words we ban: unlock, leverage (as a verb), synergy, elevate, seamless, game-changer, guru, hustle, "in today's landscape"
Your ban list will be personal and a little petty, and that's exactly right. That pettiness is your brand's edges. Keep adding to it every time you catch a word that makes you cringe in the wild.
Step 4: Show It With Before / Afters
Examples teach faster than rules. Take a flat, generic sentence and rewrite it in your voice. Two or three of these will teach a new freelancer — or an AI model — more than a full page of description ever could.
Before: "Our innovative solutions empower businesses to unlock their full potential and elevate their brand."
After: "You've got the ideas. I build the systems that actually get them out of your head and into the world."
Same message. One sounds like a stock photo of a handshake; the other sounds like a person. Do this for a handful of your most common message types — a welcome line, a sales pitch, a "sorry we're running late" email — and you've got a living reference you can copy from for years.
Step 5: Reuse It Everywhere (Especially With AI)
Here's where the afternoon pays for itself indefinitely. Your voice guide is not a document you file and forget. It's a tool you paste.
- Feed it to your AI. Drop the whole guide — pillars, both lists, word bank, before/afters — into a custom GPT, a saved project, or the top of your prompt. Then ask for drafts. The examples do more work than any instruction; AI is unreasonably good at pattern-matching your before/afters.
- Make it the first line of every brief. New freelancer, new tool, new channel? They get the voice guide before they write a single word for you.
- Use it as an editing checklist. Before anything ships, run it past the "never sound like" list and the ban words. Thirty seconds, every time.
- Revisit it quarterly. Your voice sharpens the more you use it. Add the new cringe words. Steal phrases from your own best-performing posts.
If you run more than one brand, this stops being optional — a separate one-pager per brand is exactly what lets me switch between them without everything blurring into the same beige internet voice. It also pairs perfectly with a one-page brand brief: the brief handles the strategy, the voice guide handles the sound.
Your Afternoon Checklist
That's the whole thing. To recap, a genuinely usable brand voice guide is one page with:
- Three or four voice pillars, each with a "means / doesn't mean"
- A "we sound like / we never sound like" pair of lists
- A word bank of words you use and words you ban
- Two or three before/after rewrites
- A note on how you'll reuse it (hint: paste it into your AI)
Build it once. Use it forever. Your future self — the one staring down a blank caption box at 9pm — will genuinely thank you.
Frequently Asked Questions
What is a brand voice guide, exactly?
It's a short reference document, ideally one page, that defines how your brand sounds in writing. At minimum it includes a few voice pillars, a "we sound like / we never sound like" comparison, a word bank, and a couple of before/after examples. It's the source of truth anyone — including AI — can use to write in your voice.
How long should a brand voice guide be?
One page, maybe two. If it's longer than that, nobody will actually use it, including you. The goal is a tool you paste and reference constantly, not a brand bible that lives in a folder no one ever opens. Keep it tight enough to skim in about thirty seconds.
How do I use a brand voice guide with AI?
Paste the whole thing into your AI tool — a custom GPT, a project, or the top of your prompt — before you ask for drafts. The before/after examples matter most; AI pattern-matches them far better than it follows abstract instructions. Then edit the output against your "never sound like" list. That combo gets you most of the way to on-brand copy.
What's the difference between a brand voice guide and a brand brief?
A brand brief covers strategy — who you're for, what you stand for, what you offer. A voice guide covers sound — how all of that actually gets said. You want both, and they're stronger together: the brief keeps you on-message, the voice guide keeps you on-tone.