Skills 101
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Teach Claude something once so you never have to explain it again. This session takes you from "I keep repeating myself to Claude" to "I built a skill that does it my way, on its own." Go at your own speed. Nobody is waiting on you, and you can't fall behind.

How this works

Three sections that build on each other: first understand what a skill is and spot the ones hiding in your own work, then use skills other people already built, then build your own. New to skills? Start at the top and go in order.

This one assumes you've spent a little time in Claude Code already, the kind of thing From Chat to Code gets you to. If the terminal is still brand new, do that first and come back.

We won't assign you a skill to build. Bring something you keep repeating to Claude, or pick from a menu when you're ready. Both work.

What a skill is

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Before you install anything or build anything, get clear on what a skill actually is and start spotting the ones hiding in your own work. This is where everyone begins.

Skill 1What a skill actually is

You've probably noticed you explain the same things to Claude over and over. How you like your emails to sound. The way you format your weekly update. The steps you go through to publish a post. Every new conversation, you say it again.

A skill is that explanation, written down once. It's a small folder with a plain-English file inside, and Claude reaches for it on its own the moment your request matches what it's for. You don't paste anything. You don't remember to turn it on. Claude sees the task, recognizes "this is the invoicing one," and pulls up your instructions automatically.

The shift to hold onto: a skill isn't code, and it isn't a setting you flip. It's a note to a coworker who has perfect memory. You write down how you like something done, once, and from then on they just do it that way.

It helps to see where a skill sits next to things you already know:

  • A prompt you paste is one-time. It helps this conversation, then it's gone.
  • A project memory file (a CLAUDE.md) is always-on background. Claude reads it every session, whether it's relevant or not.
  • A skill is on-demand know-how. It sits quietly until a task matches it, then it loads. That's what makes it feel less like a tool and more like a coworker who just knows how you work.
Mark complete when: you can explain, in one sentence, the difference between pasting the same prompt every time and having a skill that fires on its own.
Skill 2Spot what's worth turning into a skill

Here's the simple test: if you've explained the same preference to Claude three times, that's a skill waiting to happen. Anything you do in a repeatable, "here's how I like it" way is a candidate. One-off tasks aren't. Skills earn their keep on the things you come back to again and again.

Let Claude help you find yours. Open Claude Code (or the desktop app) and paste this in:

Paste this into Claude
I'm learning about Claude skills. A skill is a repeatable "here's how I like it done" task worth teaching you once. Interview me one question at a time about my work, my side projects, and my home life to find the things I probably repeat a lot. Use each answer to dig into the next question. When you have enough, give me a list of 5 things in my life that would make good skills, and for each one say in a sentence what it would do and when it should kick in.

If nothing comes to mind, these are the kinds of things people turn into skills:

  • Your writing voice, so everything Claude drafts sounds like you and not like a robot
  • Your weekly report or status update, in the exact format your boss expects
  • How you triage a messy inbox down to what actually needs a reply
  • Your meal plan, built from what's in the fridge, in the shape you actually cook from
  • Your invoice or quote, with your terms, numbering, and wording every time
  • Your social captions, in your brand's voice with the hashtags and sign-off you use
  • Meeting notes turned into decisions and next steps, formatted the way your team reads them
  • A packing list for your family's usual kind of trip
  • The conventions on a project you build in, so Claude writes code the way your codebase already does
Watch out for: trying to make a skill out of something you'll do once. If it's not repeatable, a normal conversation is the right tool. Save skills for the patterns.
Mark complete when: you have a written list of at least 3 things in your own life that could become a skill.
Skill 3Look inside a real skill

A skill is less mysterious than it sounds. It's a folder with one main file inside called SKILL.md. Open it and you'll find two things that matter most: a name, and a description. Then plain-English instructions, the same kind you'd type to Claude yourself.

The description is the important part, because the description is the trigger. It's the sentence Claude reads to decide "is this the moment to use this skill?" Everything about whether a skill fires when you want it to comes down to how that one line is written. Keep that in your back pocket. It matters a lot in Section 3.

See one from the inside. In Claude Code, paste this:

Paste this into Claude Code
Show me one of the skills you have available and walk me through its SKILL.md with me. Point out the name, the description, and the instructions. Then explain, in plain English, exactly how you decide when to reach for that skill and why its description is worded the way it is. Go slowly, I'm learning how skills work.
If Claude doesn't have any skills to show yet, ask it to write out an example SKILL.md for a made-up skill and explain each part. You'll install real ones in the next section.
Mark complete when: you've read a real (or example) SKILL.md and can point to its name, its description, and its instructions, and you know which one is the trigger.

Use skills others built

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Same idea as Section 1, but someone already did the writing. There's a whole ecosystem of ready-made skills you can add in a minute. Here's where they live, how to add one, and how to stay safe doing it. Do Section 1 first.

Skill 4Where skills come from

You don't have to write every skill yourself. People share them, the same way people share recipes. Anthropic publishes an official, open set on GitHub, and there's a growing collection of community ones too.

Two places worth knowing:

  • The official skills, on GitHub. They live at github.com/anthropics/skills. Open that page in your browser and you can read each one, in the same plain SKILL.md format you saw in the last section.
  • The plugin menu, right inside Claude Code. Skills often come bundled into "plugins," which are just tidy packages of skills. Type /plugin in Claude Code and you get a menu to browse and add them without leaving your terminal.

Some of the most-loved skills are the document ones. They let Claude hand you a real, finished file instead of text on a screen:

  • Turn a rough outline into an actual PowerPoint deck (pptx)
  • Produce a properly formatted Word document (docx)
  • Fill in or read a real spreadsheet (xlsx)
  • Read, combine, or create PDFs (pdf)
  • Review your own code for bugs and rough edges before you ship it (code-review)

Go look at one for real. Open github.com/anthropics/skills, click into a skill, and read its SKILL.md. Notice it's the same shape you already understand: a name, a description, and instructions.

Mark complete when: you've opened a real public skill (on GitHub or in the /plugin menu) and can name one you'd actually use.
Skill 5Install one and watch it work

Adding a skill is quick. The friendly way is the menu, and there's a one-line way too. Both are fine.

Do this
  1. Open the menu. In Claude Code, type /plugin and press enter. You'll see a browsable list you can search and add from. This is the no-memorizing path.
  2. Or add one by name. If you already know what you want, you can skip the menu and run a single command. The one below installs the official skill-builder, which you'll use in the next section anyway.
$ /plugin install skill-creator@claude-plugins-official

Now use it. Pick a skill you added and give Claude a real task that should call for it. If you installed a document skill, try something like "turn these notes into a one-page Word doc" or "make me a short slide deck from this outline." Watch Claude reach for the skill on its own and hand you a finished file.

If a skill won't budge for you, just ask Claude out loud: "what skills do you have available right now, and how do I turn on the one for making slide decks?" Using Claude to set up Claude is completely fair, and it's faster than hunting through menus.
Mark complete when: a skill you didn't write is installed, and you've watched it fire on a real task.
Skill 6What to be careful about

A skill isn't just a note. It's a set of instructions Claude will follow, and some skills also bundle little scripts that run on your own computer. That's what makes them powerful, and it's also why a stranger's skill deserves a second look before you trust it. Think of it like a recipe from the internet that also does your dishes. Worth reading first.

Three things to check on anything you didn't write:

  • The source. Is it from Anthropic's official set, or a person or team you have reason to trust? When you're new, stick to reputable sources. Official and popular is a safe place to start.
  • What it runs. Does it include commands that do things on your machine? You want to know what those are before you say yes.
  • Hidden instructions. Because a skill is text Claude obeys, a sneaky one could try to tell Claude to ignore your other rules, or quietly send your files somewhere. Read the instructions for anything that feels off.

The easiest way to check is to have Claude read it for you before you commit. Paste this in:

Paste this into Claude Code
Before I install this skill, read its SKILL.md and any scripts it comes with, and tell me in plain English: what it does, anything it would run on my computer, where it came from, and whether anything in it tries to override my other instructions or send my files somewhere. Flag anything that looks risky, and tell me straight whether it's safe for a beginner to install.
Watch out for: a skill whose description doesn't match what its instructions actually do, one that runs commands you don't understand, or one that tells Claude to ignore what you've said. Any of those, walk away. There's always another skill.
Mark complete when: you've had Claude vet a skill before installing it, and you can name the three things to check: the source, what it runs, and any hidden instructions.

Build your own

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The real payoff, and the part that opens the most doors. Build a skill that's yours. It's the same move you've practiced all along, talk to Claude like a coworker, pointed at teaching it something once so it sticks for good. Do the first two sections first.

Skill 7Decide what to build

You already did the hard part back in Section 1, when you listed the things you keep repeating. Now you pick one. Don't try to build three. One good skill you'll actually use beats a pile of half-finished ones.

There are two good ways to choose, and both are right:

  • Build the one from your own list. Look at what you wrote down in Skill 2 and pick the thing you'd use this week. Most useful, easiest to describe, most repeated. That's your first skill.
  • Or build the one everyone wants. If nothing jumps out, build a "sounds like me" skill: a house-style skill that makes everything Claude writes for you land in your own voice, with the words you use, the ones you'd never use, and the feeling you want people to have when they read you. It's evergreen, and you'll reach for it constantly.

Not sure which? Talk it through. Paste this in and let Claude help you choose the best first one:

Paste this into Claude
Help me pick the single best skill to build first. Here's my list of things I repeat a lot: [paste your list from Skill 2, or say "I don't have one yet"]. Ask me one question at a time about which of these I do most, which is easiest to pin down in clear steps, and which would save me the most time. If my list is thin, suggest a "sounds like me" writing-voice skill and help me decide if that's the right first one. When we're done, tell me the one skill to build and, in a sentence each, what it does and exactly when you should reach for it.
Mark complete when: you've picked exactly one skill to build, and you can say in a sentence what it does and when it should trigger.
Skill 8Build it with Claude

Here's the good news: you don't hand-write the file. There's a skill whose whole job is helping you make skills, and you installed it in Section 2. It interviews you, then writes the SKILL.md and puts it in the right place for you.

If you skipped that install, add it now:

$ /plugin install skill-creator@claude-plugins-official

Then describe what you want and let Claude build it. Paste this, filling in your one skill:

Paste this into Claude Code
Help me build my own skill. It should [describe what it does, in your own words]. Ask me one question at a time about exactly what it should do, the steps you'd follow, and the way I like the result. Most important, ask me about when you should automatically reach for this skill, so we can write a description that triggers reliably without firing on unrelated things. When you have enough, create the skill in the right place and show me the finished SKILL.md, and walk me through what you wrote.

Answer its questions like you're briefing a sharp new assistant. Talking it out loud is fine. The more real detail you give about how you actually like the thing done, the better the skill.

Watch out for: a vague description. Remember from Section 1, the description is the trigger. "Helps with writing" is too broad and it'll fire on everything, or nothing. Spend your care here. Say clearly when the skill should and shouldn't kick in.
One habit worth keepingWhen Claude finishes, actually read the SKILL.md it wrote, the way you learned to vet a skill in Skill 6. It's yours now, and reading it is how you learn to make the next one even better.
Mark complete when: your skill exists as a real SKILL.md in your skills folder.
Skill 9Trigger it, then make it sharper

A skill isn't really done until it fires on its own when it should. So test it the honest way. Go do a real task that ought to trigger your skill, and don't mention the skill by name. See if Claude reaches for it.

Two things can happen, and both are easy to fix:

  • It fired when it should have. You're done. Go use it.
  • It didn't fire, or it fired at the wrong time. That's a description problem, not a you problem. You just tune the trigger.

When it needs tuning, paste this:

Paste this into Claude Code
My skill didn't trigger the way I wanted. I was trying to [describe the task you gave it] and I expected it to use my [skill name] skill. Read its current description, then rewrite it so it reliably fires for tasks like that, without firing on unrelated things. Show me the before and after, and explain in plain English what you changed and why.

Run the real task again. Adjust again if you need to. This little loop, try it, watch, tweak the description, is the whole craft of making skills that actually work. Once you've felt it click, you can build a skill for anything.

Where the trail goes next: you can share your skill with other people on GitHub, stack a few related ones into a plugin, or just keep building your own quiet toolbox of "here's how I like it" skills until Claude works the way you do. There's no finish line. There's just the next thing you teach it.
When you want people building alongside you: Skills 101 is a solo path, on purpose. But it's more fun with a few others a step ahead and a step behind you. AI Trailmates runs guided programs where you build real things with a small group. Come take a look →
Mark complete when: your own skill has triggered on its own on a real task, and you've refined its description at least once.

You built a skill.

You know what a skill is, you can use the ones other people made, and you've got one of your own that fires on its own. That's the whole loop. Go teach Claude the next thing.