I usually listen to music that relates to the mood of the page/panels I'm working on. I was a musician all throughout high school and we always made stories as a band. We'd get new music and just listen to it first, not even read the sheets with it. Afterwards we would talk about the composer's intentions and ideas about the story or ideas behind the music.
Then we'd sit together and make a story to go with it, going measure by measure, note by note to make a song with a story. I kinda still do that but reversed. I think of the story or drawing I'm making a choose a song that I feel fits that to serve as a way to channel the emotions I want to put in the page. ouo
Works for me and people seem to be feeling what I want them to. :'D