Picking Coordination Exercises
A long while ago I posted this hybrid picking exercise. I've recently gone back to it and extended it a bit. Here are some variations.
The idea here is to develop the discipline of knowing exactly which finger should be picking each string, so that you don't get tangled up on long improvisational lines. Each bar applies the pattern to an A minor scale in 5th position (except a couple that shift positions) and of course you should apply the same idea to everything you can possibly imagine.
Have fun and don't overdo it -- short, frequent bursts are better than grinding these out until your elbow falls off.