I use Gary's technique. I have two sets of buffing wheels, and four compounds. One set of wheels is a pair of stiched ones, and the other is a pair of unstiched. I use a pair of each. Be careful around the edges! They can grab a corner real quick.
Depending on how bad a shape the part is in, makes the decision as to which compound to start with. Sometimes it's just the white (finest) or I may have to start with the red (next in line). Then clean with an aluminum safe cleaner to remove the residue.
On a badly scratched or discolored part, I may start withthe black (coarsest) or brown. Then follow up to the white. They sparkle like glass!
Bill <><