There's a terrific article in the latest COW Magazine called "Finding the Way to Real Money, Full Time" -- and I'm not just saying that because I wrote it. What I did was mostly organize some great information. The heavy lifting was done by some of the industry's top After Effects artists, but it's very much oriented around tips for anyone who wants to move into full time production.
In particular, there's an extended section on demo reels -- different approaches to graphic treatments, length, style, and more. Anyone interested in demo reels (which I assume is anyone reading this) should check it out.