I usually make up my own, but over time I also saved a baseline for whenever I need a soundtrack to keep focus but don't have time to select or search, just click.
It was mainly piano and cello in the beginning, but I then added more stuff. But only instrumental songs, some soundtracks, some jazz, lot of other stuff ;-)
You can have a look if you will (I built it to play it with shuffle on, ie no speical ordering in mind when I added stuff) open.spotify.com/user/sebportebois/playlist/3eKkI…