Public Ideas — I’ve played guitar for 20 years and I’m not using it for anything. What would you do with my skills?

YouTube or TikTok channel? With 20+ years of playing, plus writing songs on the spot and learning tunes by ear, you’ve got plenty to show. This also builds an audience you can later monetize through courses or Patreon.

how about custom songs as gifts? that’s a whole thing now, people pay for a song about their partner or even their dog (or cat:))

You can make instrumental packs, then license them for other people's YouTube channels, commercials, podcasts, Indie games, and films. You could find these on platforms like Artlist, Pond5, AudioJungle, Motion Array, and Epidemic sound (though it requires a submission process).

Since you prefer low-commitment projects, a singer-songwriter with finished demos could be a good match for one recording session at a time. Your ability to learn by ear would help turn rough songs into arrangements quickly. You could agree a session fee and recording credits before each project.