How to use AI to write your marketing content (without sounding like a robot)

You've tried it. You opened ChatGPT, typed "write me an Instagram post for my bakery," and got something that sounded like it was written by a corporate PR team describing a bakery it had never visited. Phrases like "indulge in our artisanal offerings" from a business whose owner just calls them "the good croissants."

That's not an AI problem. That's a prompt problem — and it's fixable in about ten minutes.

AI is genuinely useful for marketing content. Business owners using it report getting their first draft done in a fraction of the time, posting more consistently, and spending less mental energy on the blank-page problem. But the ones whose content actually sounds good didn't just ask AI to "write a caption." They gave it something to work with.

This guide shows you exactly what that looks like — including a method for capturing your voice, eight copy-paste prompts you can use today, and a full workflow for writing a week of content in 30 minutes.

Why AI content sounds like a robot (and the one thing that fixes it)

Here's what's actually happening when you get generic output: AI writes toward the average of everything it's ever read. That's billions of web pages, blog posts, and marketing copy — most of which is forgettable. When you give it a vague brief, it produces vague content. Not because it's dumb. Because you didn't tell it anything that made your business different from anyone else's.

Think of it like hiring a temp worker on their first day. They're capable. But if you just hand them a task and walk away, they'll do it the safest, most generic way possible. Give them some context — how you talk to customers, what you care about, what you definitely don't say — and suddenly they're useful.

The fix is simple: your voice has to be in the prompt. Not implied. Actually in there.

Try this right now. Copy your last three social media posts or emails and paste them into ChatGPT. Then ask: "Based on these examples, describe my brand voice in five bullet points." Read what comes back. That description — refined a little — becomes the foundation of everything that follows.

The Voice First method: how to train AI to write like you

The most common mistake business owners make with AI content is going straight to the task. "Write me a Facebook post about our new hours." The AI doesn't know who you are, how you talk, or what your customers actually care about. So it guesses — and guesses generically.

The Voice First method fixes this with a one-time 10-minute exercise that pays off every single time you create content going forward.

Step 1: build your voice document

Open a blank document and answer these seven questions in plain, honest language. Don't overthink it — write the first thing that comes to mind:

How would you describe your business to a friend over coffee? (Not your elevator pitch. The real version.)
What are three words you'd use to describe your vibe or personality?
What are two or three phrases you actually say to customers all the time?
What's the #1 frustration your customers come to you with?
What's something your competitors say that makes you cringe?
What do you never want to sound like? (Corporate? Salesy? Over-the-top cheerful?)
Who is your ideal customer in one sentence?

That's your voice document. It's maybe 150 words. It is also the most important thing you'll ever paste into an AI tool.

Step 2: use it in every prompt

The prompt structure that works is this:

[Paste your voice document]

Now write [content type] for [specific context].

Keep it [length]. Do not use the phrases [list anything you hate].
Give me 5 versions so I can choose the best one.

That's it. No magic. Just context.

Step 3: save it so you never paste it again

In ChatGPT: go to Settings → Personalization → Custom Instructions and paste your voice document there. It will be included in every conversation automatically.

In Claude: start a Project, add your voice document to the Project Instructions, and use that Project for all your content work.

In Gemini: use the "Gems" feature to create a custom AI with your voice baked in.

This is a 5-minute setup that saves you the paste every single time.

Before and after: the same brief, two ways

Here's what happens when you use the Voice First method versus skipping it.

The brief: "Write an Instagram caption for a bakery announcing fresh sourdough on Friday mornings."

Without your voice document:

Start your Friday morning right with our freshly baked sourdough bread! Made with love and the finest ingredients, our artisanal loaves are available every Friday morning while supplies last. Come in and indulge in the taste of quality craftsmanship. See you soon! 🍞✨

With a voice document that says: "We're a neighbourhood bakery. Warm, direct, a little dry humour. Our customers are regulars who know us by name. We never say 'artisanal.' We talk like real people."

Sourdough Friday is back. We pull the first loaves at 7am and they go fast — usually gone by 10. No pre-orders, no reservations. Just show up early and bring a bag.

Same brief. Completely different content. The second one sounds like a human runs the place.

Prompts that get usable copy vs prompts that waste your time

A good content prompt has four parts:

Role: who the content is for and what platform it's going on
Context: what's happening, what's the offer, any relevant detail
Task: exactly what to produce
Constraints: length, tone, what to avoid, how many versions

Here are eight ready-to-use prompts. Replace the brackets with your specifics.

Instagram caption

[Paste voice document]

Write an Instagram caption for [describe the post — product, event, moment].
Keep it under 150 characters. Conversational, no hashtags in the caption itself.
Give me 5 versions.

Facebook post

[Paste voice document]

Write a Facebook post announcing [offer/news/update].
Audience: local customers who already know us. Warm, brief, direct.
Include a clear call to action at the end. 3 versions.

Email subject line

[Paste voice document]

Write 10 email subject lines for a [seasonal promo / announcement / newsletter].
Mix approaches: some curious, some direct, some urgency-based.
Under 50 characters each. No emojis.

Promotional email body

[Paste voice document]

Write an email to our customer list about [offer].
Structure: one-line hook, 2-3 sentences of context, clear CTA, sign-off.
Under 200 words. Sound like a person, not a marketing department.

Google Business update

[Paste voice document]

Write a Google Business post about [update / event / offer].
Under 300 characters. Local, friendly, specific.

Customer review response

[Paste voice document]

Write a response to this customer review: "[paste review]"
Keep it genuine, brief, and personal — not a template. Under 75 words.

Seasonal sale announcement

[Paste voice document]

Write a [platform] post announcing [sale details].
Don't lead with the discount — lead with what the customer gets.
Clear CTA. 3 versions.

Blog intro paragraph

[Paste voice document]

Write the opening paragraph for a blog post titled: "[title]"
Hook the reader with a relatable problem or moment in the first sentence.
No "As a small business owner" openings. 3 versions.

One technique that will save you more time than anything else

Always ask for 5 versions. Every time. It sounds like overkill until you realise you'll spend 20 seconds picking the one that's 80% there instead of 20 minutes trying to edit one mediocre draft into something usable.

The 30-minute workflow: from blank page to a week of content

This workflow assumes you want to post 3–5 times across platforms this week and write one email. It works for any type of business.

Before you start: have your voice document open and know roughly what this week is about — a promotion, a seasonal moment, something happening in the business, or just a useful tip you could share.

Minutes 0–5: brief the AI on the week

Open your AI tool of choice. Paste your voice document. Then add:

This week I want to post about [theme/event/offer].
My channels are [Instagram / Facebook / email — whatever applies].
I'll give you individual prompts for each piece of content.
Keep this context in mind.

You're setting the session up so every prompt that follows is already in context.

Minutes 5–15: generate your raw drafts

Work through each content type using the prompts from the previous section. Ask for 5 versions of each. Don't edit yet — just generate. Speed is the point here.

By the end of this window you should have: 3–5 social captions, 2–3 email subject lines, 1–2 email drafts, maybe a Google Business post.

Minutes 15–22: pick and personalise

Read through what you have. Pick the version that's closest to right. Then add the thing AI can't add: a specific detail, a real anecdote, your name, something that happened in your shop this week. One or two sentences. That's the 20% that makes it yours.

Minutes 22–30: schedule or publish

If you use Buffer, Later, or Meta Business Suite, queue everything now while you're in the flow. If you send email through Mailchimp, Beehiiv, or Kit, paste the draft in and set it up.

You're done. One session, one week covered.

Real before/after examples

Example 1: a gym's January email subject line

Generic version:

Start your fitness journey today with our New Year special!

Voice First version (for a no-nonsense, locally-owned gym with a "we're not a spa" attitude):

January is loud. We'll be quiet about it.

Same offer. One sounds like every gym email you've ever ignored. The other makes you curious enough to open it.

Example 2: a plumber's Instagram caption

Most plumbers have no social presence because they figure their work isn't "Instagrammable." It is — if you're honest and specific about it.

Generic version:

Need emergency plumbing help? Our expert team is available 24/7 to handle all your plumbing needs. Fast, reliable, professional. Call us today! 🔧

Voice First version (for a family-run plumber who is blunt, reliable, and a little funny):

We got a call at 11pm on Christmas Eve. Burst pipe under the kitchen sink. Family of seven, turkey in the fridge.

We were there in 40 minutes.

That's the job.

No emojis. No "expert team." Just a true story that tells you everything you need to know about who to call.

Example 3: a bookkeeper's blog intro

Generic version:

As a small business owner, you know that tax season can be a stressful time. With so many deadlines and requirements to keep track of, it can be easy to feel overwhelmed. That's why it's important to be prepared...

Voice First version (for a bookkeeper whose clients are tradespeople and small retailers):

Every year around February, I start getting the same call. "I've got a bag of receipts, a spreadsheet that stopped making sense in October, and my accountant wants everything by the 15th. Help."

Here's how to get from that bag of receipts to a clean set of accounts — without losing a weekend.

The first one starts with what the reader already knows. The second one starts with a scene they've lived. One earns the click; the other earns the back button.

What all three examples have in common

They're specific. A gym with an attitude. A plumber on Christmas Eve. A bag of receipts. That specificity is 100% yours — AI can't invent it. But AI can build the structure around it once you hand it over.

The pattern is: AI handles the scaffolding, you supply the detail that makes it real. Every piece of content that actually lands works this way, whether or not AI was involved.

Your first 20 minutes with this

Don't try to implement everything at once. Here's the only thing that matters right now:

Open ChatGPT, Claude, or Gemini — whichever you have.
Answer the seven voice document questions above.
Paste your last three posts or emails and ask the AI to describe your voice.
Combine the two into a single voice document, roughly 150 words.
Save it somewhere you'll find it.

That's it. Do that today and you've done the hard part. Everything else — the prompts, the workflow, the scheduling — is just execution on top of that foundation.

Want the voice document template and all 8 prompts in a single copy-paste file? Subscribe to AInstein and we'll send it straight to your inbox — along with a weekly briefing on the AI tools and tactics that are actually useful for running a small business.

Next up: 10 hours of admin work you can hand to AI this week — once you've got your content covered, here's where the real time savings are.