Play to your talents. For example, I have always been good at graphic design, but I don't have the time to do it professionally, so I go for the "crap jobs" that most design shops aren't interested in.
Another example, I play several instruments. Right now I'm playing sax and clarinet for a local musical. It's not much money, but still a decent gig. And I've gotten where I've played around enough now, that I can always call up a few guys and get a full band together for other gigs (restaurants, business parties, etc.) And, it's something I enjoy doing.
As was said above, most part time jobs are pretty flexible. I'd generally advise against food service, even though if Starbucks is hiring, I'd definitely consider there.
Also, sometimes the best jobs are those where you can get paid "under the table." Help out your neighbors with yard work, and that kind of thing.
Also mentioned above, colleges have a lot of work opportunities on campus too. For a while I did a lot of work with the writing department at once facility.