I always do Music Advent (which happens primarily on Twitter) - I don't know how long that's been going on in December, maybe 5 years? I think other people frankly put a lot more thought into it than I do, but still, I manage. Sometimes I get a few days ahead, but doing a whole playlist in advance? Probably never gonna happen, with me. Anyway, this year the theme is covers. So far I've only come up with famous artists playing other famous artists - hopefully I'll manage to get in some less-famous ones as well. The way I've been coming at this is to look for artists I like, or songs I particularly like. I was actually looking for somebody else covering Pearl Jam, but so far that's mostly led me to Pearl Jam doing covers of other artists, which is also cool (and Pearl Jam does that a lot) but I don't want to just post 25 days of Pearl Jam singing covers, either. (I do have a Spotify playlist with some covers on it so I'll probably go browse around in that eventually and see what's in there. And I'll probably do some Christmas songs later on, because I do have a lingering fondness for Christmas songs still.)
The first day didn't end up being Pearl-Jam-related at all, it was Prince doing "Creep" at Coachella, ten years ago. I love this song and I'd never heard this cover.
(Note: I've had some trouble with the embeds in past years and I think I'm going to just post them here daily rather than try to do several days at a time like I've done in the past. That seems easier.)