Instead of a trot using 3 fingers, use 4.
It is kind of hard to get use to but it sounds nice and really helps you to play alot of heavy fast metal song with your fingers.
Anywho, just thought I would throw that out there... try it out
I find it insanely useful when I try to learn metal songs with my fingers... currently trying to tackle the song Wind of Horus - Nile.