CUSTOM INSTRUCTIONS SETUP

Set custom instructions once and every chat gets better forever. The 7-line setup that takes 5 minutes and changes 90% of your interactions. The single most underused Claude feature for new users.

THE PROBLEM

Default Claude is generic. Every chat starts blank. You re-explain who you are, what tone you want, what to skip. By the time context is set, half the chat is over.

Custom instructions fix this. Once. Forever.

THE SKILL

5 minutes. 7 lines. Set it now. Every future conversation reads these first.

THE 7-LINE TEMPLATE (steal this)

Open Claude.ai → Settings → Customize / Profile → Custom Instructions. Paste:

1. WHO I AM: [1 sentence — name, role, context]
2. WHAT I DO MOST: [1 sentence — primary work]
3. TONE I PREFER: [1 sentence — formal/casual, warm/direct, etc.]
4. NEVER USE THESE PHRASES: [list any AI tells you hate — "delve into," "circle back," em dashes, etc.]
5. ALWAYS DO: [your defaults — "answer first then explain," "give numbered lists when 3+ items"]
6. NEVER DO: [your no-no's — "don't suggest 5am routines," "don't mention specific apps unless I ask"]
7. THE ONE THING TO REMEMBER: [the most important thing about how you work]

That's it. Save. Done.

REAL EXAMPLE (mine)

1. WHO I AM: Fadia, a mom building a 100-day Claude skill series for stretched-thin people.
2. WHAT I DO MOST: Writing skills + articles, planning content, managing client relationships.
3. TONE I PREFER: Warm but direct. Honest. Anti-grift.
4. NEVER USE THESE PHRASES: "delve into," "leverage," "circle back," "I'd be happy to help with X." Em dashes only when natural.
5. ALWAYS DO: Answer first, reasoning second. Specific examples beat abstract advice. Cite numbers when relevant.
6. NEVER DO: Don't recommend specific tools unless I ask. Don't moralize. Don't add "I hope this helps" closers.
7. THE ONE THING TO REMEMBER: Receipts beat promises. Real numbers > polished language.

Notice: it's specific. Not "be helpful and friendly" (everyone says that). Real preferences with edge.

3 THINGS YOU CAN'T SKIP

1. Be specific. "Be casual" is useless. "Use contractions, no em dashes, sign off with just my name" is useful.

2. Include forbidden phrases. This is where you reclaim your voice. List the exact words you hate.

3. Update every 90 days. Your needs shift. Re-read the instructions every quarter and tighten.

WHAT THIS DOES (in 1 week)

Email drafts come back in your tone, no rewriting needed
Lists are formatted how you actually want
Recommendations come without the apps you've explicitly excluded
Closers don't have "Hope this helps!" anymore
Claude stops adding hedging language you find annoying

Compounds across hundreds of conversations.

INSTALL

Where to set custom instructions varies by platform:

Claude.ai web: Settings → Profile / Customize
Claude.ai mobile: Tap profile → Customize
Claude Code: Add to your ~/.claude/CLAUDE.md file (global) or project CLAUDE.md (project-specific)

Either way: paste the 7-line template, fill it in, save.

THE FULL SKILL FILE

(See SKILL.md in the share folder.)

SAFETY CHECK

Same as Day 1. Note: don't include passwords, financial accounts, or sensitive data in custom instructions — they're stored in your profile.

WHAT'S NEXT

Day 8 of 100. Tomorrow: Day 9 — The 5-Excuses Killer (for any AI-skeptic friend you want to recruit).