A skill is just a set of instructions you hand Claude once, so it knows how to do a specific job whenever you ask. You set it up a single time, and from then on Claude loads it automatically when it's relevant. No re-explaining, no pasting the same long prompt every time.

The video showed one called Last 30 Days, which turns Claude into an actual research tool instead of something that guesses from old training data. Here's the full setup for that one, then the rest of my favorites and exactly where to get them.

The one from the video: Last 30 Days

By default, Claude answers from training data, which has a cutoff date and goes stale fast. Last 30 Days fixes that. Add it to any question and it goes out, pulls what people have actually been saying this past month, ranks everything by real engagement, and hands you an answer backed by the receipts.

And it doesn't just check one place. It pulls from across the whole internet:

  • Reddit threads and top comments, with the upvote counts
  • X posts and reactions
  • YouTube video transcripts
  • TikTok captions and engagement metrics
  • Instagram Reels transcripts
  • Pinterest pins
  • Threads and Bluesky posts
  • Hacker News for developer discussion
  • GitHub repos, pull requests, and release notes
  • Polymarket for where people are actually betting money on an outcome
  • Digg news clusters and Perplexity grounded web search
  • Plus regular web search for blogs and articles

So instead of one stale opinion, you get the real picture across every corner of the internet, weighted by what actually got attention.

How to set it up (about 30 seconds)

The skill is open and free, and it lives on GitHub at mvanhorn/last30days-skill. Pick the path that matches how you use Claude:

  • Claude Code: run /plugin marketplace add mvanhorn/last30days-skill and let it install.
  • Claude desktop app: download the bundle from the repo's releases page and drag it into Settings, then Extensions.
  • Claude.ai in the browser: download the skill file and upload it under Settings, then Capabilities, then Skills.

Then use it like this. Ask your question and add /last30days at the end:

what are people actually saying about the new iPhone battery life? /last30days

It runs the searches, reads the posts, and writes you a summary backed by real quotes and numbers. A couple of the sources that scrape TikTok and Instagram want a free API key for full coverage, but it works out of the box without them.

The rest of my favorite Claude skills

Most of these are official, built by Anthropic, completely free, and sitting in one public library at github.com/anthropics/skills. You install them the same way every time: upload on Claude.ai under Settings, Capabilities, Skills, or add them in Claude Code.

Humanizer

Takes anything that reads like a robot wrote it and strips out the AI tells: the em dashes, the "in today's fast-paced world," the forced three-item lists. Run any draft through Humanizer and it comes out sounding like a person actually wrote it. This is the one I lean on most for writing.

The document skills: PowerPoint, Excel, Word, PDF

These four turn Claude into a file factory. Ask for a slide deck and it builds a real .pptx you can open in PowerPoint. Ask for a budget and it hands you a working .xlsx with the formulas already in. Same for Word documents and for filling out PDFs. No more copy-pasting text into a blank file yourself.

Skill Creator

The one that makes all the others possible. Describe a repetitive task you keep doing, and Skill Creator builds you a custom skill for it. If you ever catch yourself pasting the same instructions into Claude over and over, this is how you turn that into a one-time setup. It's how I build the skills I use for my own content.

Why these beat a normal prompt

A prompt is something you type once and forget. A skill sticks around. It loads the moment it's useful, it carries its own instructions and tools, and it stays consistent every single time. Once you have three or four set up, Claude stops feeling like a chatbot and starts feeling like software you configured for yourself.

How to find more

Two places to look:

  • Official skills live at github.com/anthropics/skills. There are around 17 of them, all free, and you can read exactly what each one does before you install it.
  • Community skills like Last 30 Days are spread across GitHub. Search the thing you want plus "Claude skill" and you'll usually turn one up.

The install path is the same no matter where the skill comes from. On Claude.ai, go to Settings, then Capabilities, then Skills, and upload. In Claude Code, add the marketplace and install. Set it up once, and it's there every time you need it.

Start with Last 30 Days, it's the one that changed how I use Claude the most. Once you see how skills work, build your own with Skill Creator and you'll never paste the same prompt twice.
– Anir

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