A very simple formula worked for me: a full LinkedIn profile and a technical blog. I've found that many people land on my LinkedIn profile, then some continue to my website where they can get an idea for my skill level by looking at some blog entries. Also, the clients that come via that channel are usually high quality clients. In general, they are dev shops with too much work to handle in-house, so they're looking for an extra hand. Since they're technical people, their projects are clearly stated and expectations are realistic.