Go light to black, not black to light, and wipe the sandpaper\or blow it out before doing the next run. Also move the sand paper up a notch before the next swipe. Keep the paper clean and do the above mentioned air hose trick and you should be good to go.
If you have a black handle, maple forearm, and black collar....I run paper from close to the collar and go left over the handle, stopping before hitting any thing light colored. Then I clean the paper, wipe down the forearm and handle, then start the next run close to the handle and run over past the collar, etc.
Hope this helps,
Dave