I just like to put on long background tracks. Etrian Odyssey has good tracks so sometimes I use loops of them, or long videos like these with a bunch in a row (the first for calm scenes, the second for violence).
https://www.youtube.com/watch?v=c839K-fyGts
https://www.youtube.com/watch?v=nIVF5abBwO8
https://www.youtube.com/watch?v=c839K-fyGts
https://www.youtube.com/watch?v=nIVF5abBwO8