go drop D, and start playing barred powerchords on open, 1st, 3rd, 5th, 6th, 8th, 10th, 12th frets you can get some awesome sounds. that's one of my favorite scales to chug away on.. I'll give an example of something that may sound good.

D|---1--1--3--1---5---0--0------------0-------------6--5--5--8--0
A|---1--1--3--1---5---0--0---3-5-6----0---3--5--8--6--5--5--8--0
D|---1--1--3--1---5---0--0------------0-------------6--5--5--8--0

that's just an example, that may or may not fit well with your song.. I don't know