Lesson #3 - How to build and use Claude Skills

Every time you start a new conversation with Claude, you lose context. The workflow you described yesterday is gone today. The format you spent 10 minutes getting right wasn't saved for the next few times you need it. The rules your team follows for customer responses have to be explained over and over again.

Skills fix that. You teach Claude once, it remembers every time.

I've been building skills as part of my work at Plain, and I've been walking support leaders through this in our Claude Code sessions. The reaction is always the same. People go from "this isn't for me" to "wait, I can actually build this?" in about 20 minutes.

Before I get into the how-to, let me clear up the three things people confuse the most: the difference between skills, plugins, and MCPs.