Freelancers -- where do you find most of your work?

Great question Daniel and one that's very hard to answer especially when you're interested in them all.

I'll be the first to admit I can't do it all at one time. That's the hard part. I can do each but as an independent, clients need turn around faster than one person can do each of these layers of development. 

I'm a graphic designer and developer first. I tend to lean toward projects that have a solid ID on their end I can work with. If a client emerges that needs ID work but they have developers (assemblers) on their end, I pick those up as well. The tough part is "wanting" to do it all and seeing areas of design that I'd do something different when working with clients. But, they are the client and tend to get their way!

It's the projects that requires all of it that I partner with others who are true experts in one area over the other.

What part of the entire process are you the most comfortable? The area that doesn't take a lot of effort and you can whiz through it with minimal effort? Then prioritize the other skills based on your comfort level. From experience, I'd settle on three solid areas/services you advertise. When you speak with clients you can share other skills but if you're not willing to respond to the demand of a particular skill you're not 100% comfortable with delivering, keep that at bay until you skill-up.

You'll get there. Just be patient with yourself. And to echo Bruce again - have a plan.