A great tidbit of advice from Lifehacker (yes, I read that site a lot):
Follow your opportunity first, then apply passion later.
I like this advice for a few reasons:
1) Most of us aren't trust fund kids who can sit around waiting for the perfect opportunity that we are instantly passionate about.
And even if we were trust fund kids, that can only buy so much. You have to start somewhere, and most of us need to earn some money in the meantime.
2) Our first passion tends to be something really obvious, and it's not always the right thing.
For example, many people that work in theatre (my field of choice) started out wanting to be actors before going on to be different kinds of theatre artists, technicians, or administrators. Now, that doesn't mean we're all failed actors. It means that we first experienced theatre by watching actors work their magic on stage and knew we wanted to be a part of it. Starting out, the only job we knew about was acting. It wasn't until we started pursuing it that we realized that actors are just the most visible part of the equation - there are a whole host of people who make magic happen in theatre, and perhaps we would rather be one of them.
3) We might not even know what our passion is.
Everyone is supposed to "follow their passion", but what if you just have some things you're good at and want to live a decent life? The passion quest can almost seem shaming. Follow an opportunity, find out what gets you the most excited about it, and see where it leads you. You might
4) There are so many hidden opportunities.
Like in the theatre example, each industry has a ton of jobs that you don't even know exist until you start exploring. The best way to explore is to say yes to an opportunity and see what happens. It might not be the flashiest or most impressive job, and it might not even be in the industry you dreamt of, but it will uncover a whole host of other opportunities you never would have discovered if you hadn't started moving down that path.
Once you start moving, you start learning things: what are the actually responsibilities of this job? Are you surprisingly good at something you didn't expect? Is the part you thought would be the most satisfying kind of lacklustre? What motivates you to do your best work? Who are you working with? What do those people do? Does another industry have a similar opportunity that your skills could transfer over to?