Watch the Chromatic Man online guitar lesson by Freekbass from 50 Freekbass Licks You MUST Know
With this lick in D I am using a double-thumb technique, where your thumb almost acts like a pick. That is how I started or discovered this technique.
I was playing in a band where we were doing driving and heavy type feels, and I never liked the idea of being trapped by a pick, because that would limit what I could do with my right hand. So I started using my thumb as a pick, and using both up and down motions, which opened up a whole new world of feel and rhythm to me.
This lick is just using simple octaves, but when you do a ghost or muted up and down attack between each note, it gives the rhythm a more moving and interesting feel.