If your team uses AI regularly, I’d bet good money you already have some sort of prompt library.
But it might just be a Google Doc called “GOOD CHATGPT PROMPTS!!!”, three screenshots in Slack, or one monster prompt Andy swears “works every time” but appears to be roughly the length of The Lord of the Rings.
An AI prompt library gives all of that stuff somewhere to live. It’s a central collection of tried-and-tested prompts your team can reuse for blogs, social posts, emails, website copy, editing, research, and all the other jobs you’re already asking AI to help with.
The really clever part is making those prompts sound like your brand.
Because if your entire team is using the same generic prompts as everyone else on the internet, you can probably guess what happens next.
Generic content.
So, let’s build something better.
First things first: What is an AI prompt library?
An AI prompt library is a collection of reusable prompts built around the tasks your team does regularly.
Think of it as the shared instruction cupboard.
Instead of starting every ChatGPT conversation with: “Can you write me a LinkedIn post about…”, you’ve already got a strong starting prompt containing the information AI needs to produce something good.
Your library might include prompts for:
- Blog ideation
- Blog briefs
- Blog first drafts
- LinkedIn posts
- Instagram captions
- Email newsletters
- Sales emails
- Website pages
- Content repurposing
- Brand voice reviews
- Fact-check preparation
- Editing and proofreading
- Turning interviews into content
- Case studies
- Podcast promos
You can keep the library wherever your team already works: Notion, Google Docs, your project management system, or a shared folder.
Why your team needs an AI prompt library
The big win here is consistency.
If six people are all writing their own prompts from scratch, you’re effectively giving AI six different versions of your brand.
One person says: “Make it fun and conversational.” Another says: “Professional but friendly.” Someone else goes rogue with: “Make it punchy. Add personality. Make it pop.”
Next thing you know, your brand sounds like six different writers were involved. Because they were.
A shared AI prompt library gives everyone the same foundations.
It can help your team:
- Spend less time rewriting the same instructions
- Get stronger first drafts
- Keep tone and terminology more consistent
- Reduce those weirdly generic AI habits
- Onboard new team members faster
- Share prompts that have already worked well
- Spot recurring problems and improve the instructions over time
It also stops all your best AI prompts living with one person. Sharon going on annual leave should not bring the entire content operation to its knees.
Generic prompts give AI far too much freedom
Take this prompt: “Write a friendly and professional blog for our audience about cybersecurity.”
What does friendly mean? What does professional mean? Who exactly is the audience? How knowledgeable are they? Does your brand explain technical topics slowly and reassuringly, or get straight to the point?
Do you use humour? Are there words you hate? Are there claims you’d never make? How long are your paragraphs? Do you swear? Would your founder rather eat their own shoe than publish the phrase “in today’s fast-paced digital landscape”?
AI has literally no idea. So it fills in those gaps itself. And AI has met a LOT of “friendly and professional” brands, folks. Trust me.
That’s how you end up with content full of:
“Unlock…”
“Elevate…”
“Seamless solutions…”
“It’s not about X, it’s about Y…”
(Ew).
The more helpful information you give AI about how your brand communicates, the less guessing it has to do. Which brings us nicely to…
How to build an AI prompt library specifically for your business
So, what you gotta’ do is:
#1 Build the brand brain first
Before you spend an afternoon creating a zillion beautiful prompts, you need to know what you’re teaching them.
This is where your Brand Voice Bible comes into play.
Your Brand Voice Bible gives your team a shared understanding of things like:
- Who you are
- Who you’re talking to
- What your brand believes
- What your personality feels like
- How you explain things
- How direct you are
- How you use humour
- Words and phrases you love
- Words and phrases you absolutely cannot stand
- Formatting preferences
- Tone changes for different situations
- Strong examples of on-brand writing
Because “warm, witty, and confident” sounds lovely in a branding presentation. But it’s not remotely helpful when somebody has to write a thought piece on deadline.
Your AI prompts need the behaviours behind those adjectives.
#2 Turn brand adjectives into proper writing instructions
Say your brand is “warm”. Great. What does warm DO?
Maybe: Speak directly to the reader. Use contractions and everyday language. Acknowledge frustration without making the situation sound dramatic. Give people a clear next step.
Now we’re getting somewhere.
Or your brand is “confident”.
That might mean: Make clear recommendations. Explain the reasoning behind them. Avoid vague, unsure phrases such as “it may be worth considering”.
“Playful” could become: Use occasional cheeky observations and dry humour. We can joke about ourselves and our industry. The customer should never be the punchline. Dial the humour right down when the topic is sensitive or high-stakes.
THAT is good info for your AI to have.
When you’re building your prompt library, go through every fluffy brand adjective and ask: What would I see on the page if a writer was doing this well?
Write that down.
#3 Decide which brand voice rules every prompt needs
You don’t need to paste your entire Brand Voice Bible into every prompt. (Thank God).
Create a shorter set of core brand instructions that can live under everything else.
Here are the bits I’d include:
Who you’re talking to
AI needs to understand who is reading.
Give it information about:
- Their job or role
- Their level of knowledge
- Their main problems
- What they care about
- What they’re sceptical about
- What they probably already know
- What they’re trying to decide
Compare: Write for business owners.
With: Write for founders of growing SMEs who know the basics of marketing but don’t work in SEO or content every day. Explain technical terms clearly, and assume they’re short on time.
Much better.
How your brand writes
Include the little mechanical things too.
Things like:
- British or US English
- Oxford comma
- Typical sentence length
- Typical paragraph length
- Whether you use contractions
- Whether sentence fragments are welcome
- First or third person
- Headline style
- Capitalisation
- Emoji use
- Swearing rules
- Whether rhetorical questions are common
- How formal the language should feel
These details might sound tiny. They’re also the exact details your editor ends up correcting 59 times when they’re missing.
What your brand believes
This bit is VERY important if you want AI content to sound far more real. Give AI some of your genuine opinions.
For example:
- We believe AI should support human writers, editors, and subject experts, but not replace them.
- We think publishing more content purely because AI makes it quicker is a terrible strategy.
- We prefer clear explanations over jargon.
- We care about accurate sourcing and human fact-checking.
- We think brands should sound recognisably like themselves.
Your beliefs shape how you explain a topic, which examples you choose, what advice you give, and where you’re willing to disagree.
Without them, AI tends to float towards the safest possible middle ground. Which is where personality goes to die.
Add your banned phrase list
Ahhh, the fun section! Every brand has words that make somebody’s eye twitch. Write them down.
Your list might include:
- Corporate clichés
- AI favourites (hello “quietly” and “thrive”)
- Industry jargon
- Words your competitors overuse
- Phrases your founder despises
- Weird sentence structures AI keeps producing
- Overblown claims
- Formatting habits you dislike
For example: Avoid “unlock”, “elevate”, “seamless”, “game-changing”, “in today’s digital landscape”, and any sentence that sounds like it belongs on a SaaS homepage from 2018.
Glorious.
- You can also include instructions around recurring AI habits:
- Don’t open every section with a rhetorical question.
- Don’t repeat the conclusion three different ways.
- Don’t turn every heading into “Why X Matters”.
- Don’t make up quotes, statistics, testimonials, examples, or company claims.
That last one deserves a nice big font.
#4 Give AI examples of your best writing
Your prompt library gets much stronger when AI can see what “good” looks like. Choose a few examples that really sound like your brand.
They could include:
- A social post
- A homepage paragraph
- A newsletter intro
- A technical explanation
- A CTA
- A more serious piece of content
Then explain why you like them.
For instance: This is a strong example of our social voice. Notice the short opening, conversational language, light self-deprecating joke, direct advice, and relaxed CTA.
You’re teaching AI what to pay attention to. And please choose your examples carefully. If you feed it 25 pieces from six years of content, including three written by an intern that didn’t last 2 months, and one your CEO openly hates, don’t be mad when the output isn’t what you expected.
#5 Start with the jobs your team does all the time
Your first AI prompt library does not need 100 prompts. Start with the stuff your team repeats every week.
Blog prompts
You might have separate prompts for:
- Generating blog ideas
- Creating a brief
- Writing a first draft
- Refreshing an old article
- Reviewing for SEO, AEO, and GEO
- Repurposing the finished blog
A good blog prompt might cover:
- Audience
- Search intent
- Main keyword
- Secondary topics
- Objective
- Required sections
- Source material
- Internal links
- CTA
- Brand voice
- Fact-checking rules
Social media prompts
Create different ones for different jobs.
For example:
- Educational LinkedIn post
- Founder story
- Blog promo
- Podcast promo
- Case study
- Promotional post
- Event post
Email prompts
You could build templates for:
- Monthly newsletters
- Promotional emails
- Nurture sequences
- Client updates
Include details around your usual greeting, subject line style, humour, paragraph length, CTA style, and how salesy you’re comfortable being.
Website copy prompts
These need a little more information. But, to be honest, AI never really does a decent job of writing website copy. It’s an entirely different beast due to all the SEO and AEO requirements. But if you’re looking for a first draft, include:
- Page purpose
- Target audience
- Search intent
- Main keyword
- Secondary keywords
- Key messages
- Positioning
- Proof
- Required sections
- CTA
- Search optimisation requirements
- Brand voice rules
#6 Give every prompt the same basic anatomy
You can make your prompt library much easier to build by using a standard structure.
Something like:
1. Brand context: Who are we?
2. Audience: Who are we speaking to?
3. Objective: What should this piece achieve?
4. Source material: What information should AI use?
5. Deliverable: What are we creating?
Include format, length, channel, keyword, structure, and CTA.
6. Voice rules: How should it sound?
7. Do / don’t instructions: What needs to happen, and what needs to stay very far away?
8. Final check: Ask AI to review its work before handing it over.
For example: Before finalising, check the draft against the brand voice rules. Remove any banned phrases, repeated points, generic filler, or unsupported claims. Flag anything that needs human verification.
A little self-check won’t somehow turn AI into your senior editor. That would be crazy. It can catch some of the obvious rubbish before said editor has to look at it.
We’ll take the win.
#7 Build editing prompts too
Your AI prompt library can do loads more than generate first drafts. Some of the best prompts are for reviewing work.
Try creating prompts for:
- Brand voice checking
- Removing generic AI language
- Making wordy copy more concise
- Finding repetition
- Checking whether claims need evidence
- Comparing copy against your Brand Voice Bible
- Finding missing information
- Repurposing content without losing the original point
For example: Review this draft against our brand voice guidelines. Flag anything that feels too formal, generic, corporate, salesy, or unlike the examples provided. Explain each issue before suggesting a rewrite.
That gives your team a much more helpful review than: “Make this sound more human.”
Inside each prompt, clearly mark anything the user needs to replace:
#8 And please build in some human checkpoints
Some things still need a person with a functioning brain attached.
Your prompts should tell AI when to flag uncertainty.
For example:
- If a factual claim isn’t supported by the source material, flag it for review.
- Never invent statistics, customer quotes, case study results, credentials, awards, or testimonials.
- Flag legal, medical, financial, or technical claims that need subject-matter review.
- If the tone could be inappropriate for a sensitive topic, flag it before drafting.
Your prompt library should help AI create better work. Your humans still decide whether that work should go anywhere near the public with your name on it.
Give your AI something decent to work with
You can build the coolest, cleverest, most beautifully colour-coded AI prompt library known to humankind.
But if your team still can’t agree on what your brand sounds like, who it’s speaking to, what it believes, or what “confident but approachable” means when somebody has to write a sentence…You’ve got some homework to do first.
Our Brand Voice Bibles can help with that. Ready to build yours? Talk wordy to us.
