Prompt(s) of the week:
This week, we have 2 prompts that you can try for yourself!
#1 Subject line text generation for A/B testing
Let's start with the one that everyone talks about but few do well, subject lines.
We start by using Breeze Assistant to generate multiple subject lines and preview text variations for the same email, tailored by audience segment, so you can run meaningful A/B tests.
HubSpot's own analysis shows that AI-optimised subject lines can increase open rates by up to 30%. Personalised subject lines are reported to be 50% more likely to be opened. The HubSpot community consistently highlights subject line optimisation and segmented testing as the highest-impact, lowest-effort win when adopting Breeze. So let us give it a go.
Prompt structure
Simply paste the following prompt to your Breeze Assistant and adjust the placeholder details in CAPITAL letters for your own.
Role: You are an email marketing specialist for [COMPANY NAME]
in the [INDUSTRY] space.
Task: Generate 5 subject line + preview text pairs for a marketing
email about [TOPIC/OFFER].
Audience: [SEGMENT DESCRIPTION — e.g., "marketing managers in SaaS
companies who downloaded our whitepaper in the last 30 days"].
Goal: [PRIMARY ACTION — e.g., "get them to register for our upcoming
webinar"].
Tone: [TONE — e.g., Professional but approachable].
Constraints:
- Subject lines must be under 50 characters
- Each variation should test a different angle:
1. Urgency/scarcity
2. Curiosity/question
3. Benefit-led/value proposition
4. Social proof/data point
5. Personalised (using a personalisation token like first name or company)
- Preview text should complement (not repeat) the subject line
- Avoid spam-trigger words like "free," "act now," or all caps
Output format:
| # | Subject Line | Preview Text | Angle Being Tested |
#2 Re-engagement campaign.
Re-engagement is one of the most efficient ways to revitalise your database!
To maximise impact, segmented emails are crucial, driving 30% more opens and 50% more click-throughs than unsegmented emails.
We can ask the assistant to draft a three-part re-engagement email sequence for inactive contacts (e.g., those with no opens or clicks in the past 90 days).
This sequence should be implemented via a HubSpot workflow that uses branching logic.
The workflow's path for a contact is determined by whether they click a confirmation Call-to-Action (CTA) within the sequence.
This is highly valuable because Re-engagement campaigns are a highly effective yet often overlooked strategy for sparking new conversations with inactive contacts.
As a best practice, we would recommend a sequence of at least three emails, spaced 5–7 days apart. With tools like Breeze, generating this full sequence is fast; the copy, which is typically the most time-consuming part, is created in minutes.
Prompt structure
Role: You are a retention-focused email copywriter for [COMPANY NAME],
a [BRIEF BUSINESS DESCRIPTION].
Task: Write a 3-email re-engagement sequence for contacts who have not
opened or clicked any marketing email in the last [TIMEFRAME, e.g.,
90 days].
Brand voice: [DESCRIBE — e.g., "Warm, human, lightly humorous —
never corporate or guilt-tripping"].
Sequence structure:
Email 1 (Soft check-in):
- Acknowledge the silence without pressure
- Remind them of the value they originally signed up for
- Include one low-commitment CTA (e.g., "See what's new")
Email 2 (Value-led nudge, sent 5 days later):
- Share a specific piece of high-value content or recent result
relevant to [SEGMENT/INDUSTRY]
- Use social proof or a stat to rebuild credibility
- CTA: confirm they'd like to keep receiving emails
Email 3 (Final notice, sent 7 days later):
- Clearly state they will be removed from the mailing list
- Keep it respectful and brief
- Single CTA: "I want to stay subscribed" linking to
[CONFIRMATION PAGE URL]
Constraints:
- Each email should be under 150 words in body copy
- Subject lines should be conversational, not clickbait
- Do NOT use discounts or promotions as incentives
- Include a suggested subject line and preview text for each email
Output: Provide all 3 emails in sequence, clearly labelled.
How are good prompts built - and how to try your own!
Now that you've seen two working prompts, let's pull back the curtain. Understanding how these are structured will give you the confidence to build your own for any email marketing scenario — or anything else you can think of!
Both prompts above follow a deliberate structure. Every strong prompt has five core building blocks, and they work best when provided in this order:
- ROLE - Who should the AI "be" when writing?
- TASK - What exactly do you need it to produce?
- CONTEXT - Who is the audience, and what's the situation?
- CONSTRAINTS - What rules, limits, or guardrails apply?
- OUTPUT - What format should the result take?
If this looks familiar, it should; it follows the same structural thinking as the assistant instructions we configured in the custom Breeze Assistant from last week. The difference is that here we're crafting a single-use prompt rather than a persistent personality, but the principles remain the same.
Now, let us talk a little more about the individual building blocks:
Role sets the expertise level and perspective. Telling Breeze to act as "a retention-focused email copywriter" produces very different output than just saying "write an email." The more specific the role, the more targeted the language and strategy in the output.
Task defines the deliverable in concrete terms. Instead of "help me with email," you say "write a 3-email re-engagement sequence" or "generate 5 subject lines and preview text pairs." Breeze performs dramatically better when it knows exactly what shape the output should take.
Context is where you feed in the details that make the output relevant to your business. This includes your audience segment, their lifecycle stage, your industry, and what action you want the reader to take. This is also where Breeze's CRM integration shines — it can pull in data you reference, so naming specific segments or properties helps ground the output.
Constraints are the guardrails that prevent generic or off-brand results. Word limits, tone restrictions, things to avoid (like spam-trigger words), and structural requirements all go here. Think of constraints as the difference between a first draft you'll rewrite entirely and one you can edit lightly and send.
Output format tells Breeze how to present its work. A table, a numbered sequence, labelled sections, specifying this saves you from having to reorganise the response and makes it easier to copy directly into HubSpot's email editor.
Beyond the prompt:
Think of these two prompts as your starter kit, not the finish line. The real power comes when you start building a library of tested prompts that your team can reach for depending on the situation: product launches, seasonal campaigns, event invitations, post-purchase nurtures, and so on.
Combine this with what we covered last week on custom Breeze Assistants and you can create a dedicated assistant with email marketing expertise baked into its personality, feed it your brand voice guide via a Knowledge Vault, and have it ready for anyone on your team to use.
So go and build your own prompt library, start with these two, experiment with the five-block structure, and watch your email marketing get sharper with every iteration!
