Sort of a hobby/compulsion: designing movie, tv, and game posters in photoshop. I have a very large digital media collection, organized through Plex. But a lot of the time I hate the posters that it automatically assigns to the movies and TV shows so I find myself making my own artwork for my collection in photoshop a lot. This also led me to start designing and printing my own game covers for some of my favorites. Since those are one of the last forms of physical media I still frequently use I actually end up printing those and using it in place of the art in the box sleeve. I wouldnt call any of the custom covers phenomenal, but I just find it really calming and fun to make them, and I really like seeing my own artwork for something I love. Small thing but I enjoy doing it.
My video game ones really aren't that great, plus I do them for collections. For example I'll have a 6 disc case that has a bunch of random games and the cover is a mismash of stuff just designed to tell me what's in it. But I recommend you check out the customcovers subreddit, they have some cool stuff you might like looking at.
That's not mundane at all! Honestly, that seems really interesting. would you be willing to share some of your favorites?