Doing this myself (within reason), it is quite a bit of work actually. I have designers/devs on long-term retainer to help me out from time-to-time. I spend weeks traversing the social graph (dribbble for designers and github for devs). I research their projects, twitter (if they have it), and any other tangible deliverables. Once I find a handful, I'll meet with them face-to-face via G+, Skype, etc. If there is chemistry, proceed to the next stage where I will do a couple milestone based gigs. Usually there are two at this point. Usually one will live up to expectations, or neither will.

Repeat. Repeat. Repeat...