Ah! The GitHub trending repos usually has some rapidly rising skills projects, https://github.com/trending. https://github.com/DietrichGebert/ponytail is a good example for one gaining lots of popularity now (no affiliation, just like it).

OpenAI, anthropic, lots of companies building coding agent tools, also share skills publicly.

Skills can feel like a big productivity boost at first, but it's good to remember lots of times they represent the ways that a specific person works. That way of working may not always be right for you, or, it might hide how the work is actually being done. Good to always try out the general purpose tool as-is, looking for skills that help you repeat tasks without rewriting prompts, or help save tokens, or help your agent use tools that it may not know how to use already.