Another way to build speed is to combine both of the previous lessons and put them through what are called "Cycling Patterns" That is, playing certain licks over and over while increasing the tempo slowly, building your speed and technique in the process.
Make sure that each of these patterns are played slowly at first with just a clean setting, and then once you have the motions down, bring it up to tempo and crank up the distortion!
Lick 1:
Lick 2:
Lick 3:
Lick 4:
Now, try creating your own patterns!