CLAUDE.md Complete Guide — The File That Makes Claude Code Actually Useful

0:00 — Intro 0:30 — What CLAUDE.md actually 1:00 — Optimize your CLAUDE.md 1:50 — CLAUDE.md example 4:53 — The four-layer system 5:48 — Skills: writing custom context for your project 8:10 — Commands: reusable prompt templates 10:30 — Hooks: deterministic enforcement for non-negotiables 13:02 — Subagents: isolated claude instances 15:22 — Common mistakes Most Claude Code tutorials show you how to install it. This one shows you how to set it up so it works the way you want. CLAUDE.md: what goes in it, what doesn't, the right length, and @imports Skills vs. slash commands: which to reach for and why Hooks: deterministic code enforcement (the layer that can't hallucinate) The four-layer mental model for the whole extensibility system Claude Code docs: code.claude.com/docs — Power-user tips: support.claude.com