http://wiki.polycount.com/wiki/Freelance#Finding_Clients I just wrote this for a student friend of mine, and added it to the wiki. How do you find clients?
The best clients are the ones that find you. I get work by staying visible on polycount, providing people with help, and sharing resources for other artists.
I get emails from time to time with work offers (concept art) and all of them except for one was from people who saw my work on pinterest. I don't know how applicable this is for 3d since I figure people are more likely to scour pinterest during pre-production just to get ideas/inspiration, but figure it's worth…