Honestly the Lofi Girl channels on YouTube are probably a higher frequency go-to than I like to admit to myself

If I'm choosing from my library, I'll either go down the Brian Eno-style minimal ambient road, or probably that 95-05 era of trip hop/downtempo electronica mix of tracks running the gamut of portishead/massive attack through to stuff like telepopmusik, thievery corporation, nightmares on wax, zero 7, etc

If I'm in the right mood for it, I find a lot of aphex twin's stuff can be pretty relaxing, but I understand that's probably a less common choice