Podcasts and playlists on mine. Been a spotify user for 15 years.

Playlist are usually genre specific. With a GrabBag playlist and "comedy" playlist. Spotify is good at throwing me new songs on a solid genre playlist. Pretty easy for my house/techno, rock, and my wayback (pre-2000s) playlist.

A mix of songs kind of throws it off, like too many different types of music and it doesn't really get "taste".

If you use spotify, make playlists separated by genres. That's the best I've seen for music discovery with spotify.