The Characters/Team would be songs that I see represent a character or remind me of the character. Also I would include Team-centric songs.
Pairings would, as the name implies, be about various pairings. No way can I do every single pairing ever, but I have quite the list already. Sometimes I hear a song and just think of a pairing, whether I ship them or not, so I'd like to make a list of those songs. I'm still in the process of collecting songs I want but don't have yet for this one, though.
Fic Themes is more personal. When I write, I often listen to music to "get me in the mood." If I want to write something raw, I put on something angsty. When I want to write something sad, I'll put on something sorrowful. I never hear and a song and go "oh! I'm going to write a story about that song!" it's usually the opposite. I'll be writing, hear a song, and suddenly realize that song goes great with what I am writing. Then that song becomes sort of the theme for a scene or a fic and whenever I need to be inspired, I'll put it on. I do that will my original fic, too. I'm even making lists for me for my original fic to help me out in that area, but that's a different story. It's this memory association thing. So, as of now, I have aquiet a few songs that compliment some of the fanfics I've written.
Some of the songs for the character/teams/pairings would definitely be tongue-in-cheek because it's more fun that way.
Which mix are you interested in?
Pairings (wide range)