Depends on how pissed I am. Sometimes I'll sit down and write or I'll just isolate myself. Also, I listen to this song:
http://www.youtube.com/watch?v=3-XqpgSFnjc
It's a cover of Metallica's 'Sad But True'. Kinda odd, I know. The song makes me feel really, really pissed off when I listen to it. And when I'm already pissed and put this in the mix, I'm suddenly not mad at what I was in the first place. Before the song's even over, I'll change tracks and feel better. It's weird, but it works.