Prompt Engineering That Actually Works

Good prompts are clear, constrained, contextual, and testable. You don’t need tricks—just a simple process you can reuse and iterate.

If you’ve been stacking “secret hacks,” breathe. Great prompts feel like great product briefs: short, opinionated, and easy to verify. The aim isn’t magic—it’s reliability.

5 quick steps

1. State the outcome in one sentence (what success looks like).
2. Provide only the context that changes the answer (facts, audience, constraints).
3. Show 1 short success example (and optionally a failure to avoid).
4. Specify the output contract (format, fields, length, tone, exclusions).
5. Run → review → change one variable → rerun. Keep a prompt log.

Micro-examples (fast intuition)

• Outcome: “Draft a 90-word outreach email that gets a reply.”
• Context: “Audience: senior eng. managers; constraint: no fluff; goal: book 15-min intro.”
• Example: “Good: plain, specific, one ask. Bad: hype, 3 asks, vague offer.”
• Contract: “Format: 1 paragraph + 1 bullet CTA. Length: <= 90 words. Tone: direct.”
• Iterate: “Test 3 subject lines; keep body constant; log open/reply deltas.”

Why this works

• It reduces ambiguity: outcome + contract define success.
• It guards against drift: examples anchor style/content.
• It’s measurable: you can test and compare small changes.

Prompt template

You are [role]. Task: [one-sentence outcome].

Context:
- [facts + domain constraints]
- [audience, goals, brand voice]

Rules:
- [must/never; style; safety]
- [length limit; format requirements]

Inputs:
- [variables or data snippets]

Output:
- Format: [JSON/Markdown/plain]; Fields: [list fields]
- Length: [<= N words/sentences]
- Include: [key requirements]; Exclude: [out-of-scope]

Examples:
- Good: "[brief example that matches the contract]"
- Bad: "[common failure to avoid]"

Return ONLY the Output.

Mini example

You are a senior product marketer. Task: Write a 120-word launch note for the “Instant Sync” feature.

Context:
- Audience: existing Pro users; cares about reliability + speed.
- Feature: background sync in <1s; works offline; zero setup.

Rules:
- Tone: confident, plain language. No hype words ("revolutionary").
- Length: <= 120 words. Include a CTA link placeholder.

Output:
- Format: Markdown paragraph + 1 CTA line.

Example (Good):
"Instant Sync keeps your work up to date in under a second, even offline…"

Example (Bad):
"Introducing our revolutionary, game‑changing update!!! Experience productivity like never before with cutting‑edge cloud synergies…"

Self-critique checklist:
- <= 120 words
- Mentions <1s background sync and offline
- Plain tone (no hype words)
- One clear CTA line with link placeholder

Return ONLY the Output.

Variations to try

• Change audience to “new trial users” and shrink to 80 words.
• Keep copy fixed; swap 3 headlines; pick the best via a quick user poll.
• Ask the model to rate its own output against the checklist (0–1 per item).

Common traps (and fixes)

• Long context dump: Keep only facts that would change the answer.
• Vague asks: Replace “make it better” with a measurable outcome.
• No contract: Always specify format, fields, and length.
• Single-shot thinking: Change one variable per iteration; log it.
• Style drift: Pin a short “good” example right in the prompt.

Pro tips

• Front-load constraints. The first 3 lines do most of the steering.
• Prefer examples over adjectives. “Show one” beats “sound professional.”
• Write the contract before the content. It clarifies what matters.
• Use failure examples sparingly—they’re powerful anchors when short.

Prompt log (tiny example)

• 2025‑08‑08 V1: 120w, Pro users, plain tone. Win: highest clarity. Lose: weak CTA.
• 2025‑08‑08 V2: Added benefit-first CTA line. Win: better click intent.
• 2025‑08‑08 V3: Shortened to 95w; tightened verbs. Win: faster read; kept specs.

Last mile: test your prompt with 3 varied inputs, ask the model to self-critique against your output contract, and pin successful versions in a prompt log (date, change, win/lose). Iterate, don’t stack hacks. Ship small improvements on purpose.