When using a single-edge razor blade to score and cut brass tubing, I do the work on a piece of 600-grit wet/dry sandpaper. The sandpaper helps roll the tube as I move the blade back and forth across the tubing. This speeds up the job and makes for a cleaner cut, as the grip provided by the sandpaper keeps the blade pressure even throughout.

Tip submitted by:
Ken NilesFayetteville, Ga.