Writing instructions Claude gets right on the first try — CLAUDE.md, motivation, XML, few-shot
Series part 5
Ever caught yourself typing the same setup instructions to Claude for the fifth time in a week?
Part 4 covered 11 prompt patterns. This post is about the five techniques that sharpen any prompt template — and quietly kill the “say it again” tax.
Technique 1 — Persist project rules in CLAUDE.md
From the Claude Code best practices:
Create a
CLAUDE.mdat the root of your repository. Claude will automatically read it at the start of every session.
Put a CLAUDE.md at the repo root and Claude loads it automatically each session.
Inside, put the things you keep repeating.
Excerpt from my HomePage CLAUDE.md
## Text management rules (top priority)
- No hard-coding of UI text
- i18n: ja / en in src/i18n/ja.ts and src/i18n/en.ts
## Pre-commit checks (required every time)
1. Horizontal check
2. Security check
3. Performance check
4. Deploy check — npx astro check → npm test → npm run buildThis alone eliminated all my “please put UI text in the i18n file, not inline” instructions.
Technique 2 — Include the reason behind the rule
From the guide:
Explain the reasoning behind a rule, not just the rule itself.
State the why. Claude can then generalize to edge cases.
| ❌ | ✅ |
|---|---|
| “Don’t write comments." | "Only write comments for WHY. The WHAT is expressed by well-named identifiers, so comments just add noise." |
| "Use the i18n module." | "Centralize text in i18n so missing translations surface as compile errors at build time.” |
Reasoning enables judgment, not just compliance. Same as onboarding a new engineer.
Technique 3 — Structure complex prompts with XML tags
For prompts longer than a few lines, XML tags work wonders:
<context>
Astro v6 + TypeScript personal homepage.
Hosted on GitHub Pages.
</context>
<task>
Add scheduled publishing to blog posts.
</task>
<constraints>
- Serverless (GitHub Actions only)
- Must not break existing tests
</constraints>
<output_format>
1. Design in 200 chars max
2. List of files to change
3. Test additions
</output_format>Section boundaries alone clarify Claude’s output structure. My rule: if the prompt passes 5 lines, I switch to XML.
Technique 4 — Include 3–5 diverse examples (few-shot)
From the guide:
Including 3-5 diverse examples dramatically improves Claude’s output quality.
Write commit messages in this format.
Example 1: "fix: correct timezone bug that prevented scheduled posts from firing"
Example 2: "feat: add a calendar component to the blog"
Example 3: "refactor: extract TOC logic into pure functions for testability"
Rules:
- Start with a type (fix/feat/refactor/docs)
- One-line gist
- Explain the WHYTeaching by example outperforms prose. Less room for misinterpretation.
Technique 5 — Put long documents first, questions last
Subtle but effective. From the guide:
When working with long documents, put the document first and the question at the end of the prompt.
Place long context on top, put the question/instruction at the bottom. Attention mechanics mean the last instructions weigh heaviest.
<document>
[Paste long document here]
</document>
Given the document above, please answer:
1. ...
2. ...Reverse order (question first, doc after) can make Claude “forget” the question by the time it finishes reading.
When to use which technique
| Situation | Technique |
|---|---|
| Repeating the same project rules | 1. CLAUDE.md |
| Rules aren’t followed / don’t generalize | 2. Add reasoning |
| Prompt exceeds 5 lines | 3. XML tags |
| Need consistent output format | 4. Few-shot |
| Referencing long documents | 5. Doc first, question last |
My take — CLAUDE.md has the best ROI
Of the five, CLAUDE.md is by far the highest leverage. Write it once, benefit every session forever after.
Putting the “pre-commit checks” list into my HomePage CLAUDE.md means Claude runs tests, builds, and security checks before every commit, automatically. Done manually, I’d forget. Done as a rule, it’s permanent.
If you don’t have a CLAUDE.md yet, you might try writing just five lines today — the rules you most commonly repeat. That alone is usually enough to feel the difference.
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