AI prompts for marketing that keep your brand voice

• Audience. Who reads this, and what they care about.
• Offer. What you sell, the price and the date that matters.
• Channel and cadence. Where it goes and how often.
• Voice. How the brand sounds, in a few plain words, plus one sample.
• Limits. Dates to skip, claims you cannot make and the format of the answer.

Anthropic's blog says to give the reason behind the job and name the audience. Google's Workspace guide suggests a Persona, a Task, Context and a Format, and lets you use only some of them. For Claude, Anthropic says even a single sentence of role makes a difference.

Write voice rules as what to do. "Short, concrete sentences" works better than "no jargon", because Anthropic says to tell the model what to do instead of what not to do.

Pattern 1: a campaign brief. Prompt: Write a one-page campaign brief for the spring launch of the Saltmarsh Tea sampler, on sale 9 March. Audience: people aged 28 to 45 who buy tea as a gift online. Offer: six loose-leaf teas for £18, with free shipping over £30. Goal: 400 sampler sales in four weeks. Channels: Instagram and email. Budget: £1,500. Voice: friendly, a little funny and easy-going. Format: five headings (audience, message, channels, calendar, how we will measure), under 350 words.

Pattern 2: a post in a brand voice, with a sample. Prompt: Write a LinkedIn post for Tobias Quinn, founder of Plimsoll & Quay Software, about why we moved from annual contracts to monthly billing on 1 October. Three customers had asked for it. Match the voice of this earlier post: "We shipped less last quarter. That was on purpose. Here is what we cut and why." Short lines, first person, one idea. About 120 words. Start with a plain statement, and use one hashtag at most.

Pattern 3: turn a customer call into posts. Prompt: Here are my notes from a call with Yasmin Orr at Thornapple Crumb Bakery. She cut her ordering time from two hours to 20 minutes a week. She still uses paper for supplier invoices. She wants a phone view. She agreed we can quote her. Turn them into three LinkedIn post ideas. For each idea, give a first line and the one fact from the notes it rests on. Use only what the notes say.

A short note on keeping the AI honest: Google's Workspace guide says to review outputs for clarity, relevance and accuracy before use.

• Your voice. Without a guide and a sample, the AI writes in its own house style.
• Your facts. Prices, dates and product names are not in the AI, so you paste the product page every time.
• Your history. What you posted last month, so this month does not repeat it.
• Your dates. Cut-off days, shipping deadlines and the days the team is away.
• Your audience's words. The phrases customers use on calls, which no AI has seen.

Scrubbr keeps your brand voice guide and product facts in its knowledge base and reads them when you say the line, so you stop pasting the same page.

• Ask for a table, so you can check each row against your real dates.
• Match each price, product name and date to your product page before you schedule. Microsoft's guide says every answer needs your review and verification.
• Expect to revise. Google says to iterate: rephrase the prompt, or change the order of the examples, the context and the input.
• Read each hook aloud. If it does not sound like your brand, add a second sample to the prompt, or tell the AI which line to match.

Sources checked on 2026-11-03.

• Best practices for prompt engineering (Anthropic)
• Prompting best practices (Anthropic)
• Writing effective prompts (Google Workspace)
• Prompt design strategies (Google, Gemini API)
• Get better Copilot responses with great prompting