Picking chops....

I learnt a lot of little techniques from Paul Gilbert and John Pettrucci vids.

One thing to do though is make sure you are using the right kind of pick for your personal technique. Lots of guitarists just use the first pick that they find (or the one they started to learn with), I found that my control over my guitar increased when I switched to Jim Dunlop Jazz III picks.
 
I also use Jazz III picks and I'm never looking back. Chances are, if you're a metal player, you will appreciate the flexibility these picks give you in terms of playing faster and more fluently. I think they're a good starting point, even before you get into technique.
 
Along with the above stated suggestion, I also suggest playing along to some Iced Earth songs. Jon Schaffer is a freakin' tight ass player. His gallop is beyond tight.
 
I've always found that playing different alt. patterns with a metronome helps, start slow and when you can do it tight just keep speeding it up. Also , if you use alot of distortion turn your gain down , it will force you to play really clean.