Don't bounce around. No matter how many piles you may have, just focus on one small area at a time. Choose a single pile and go through it before you move on to the next pile. By staying focused on one area at a time, you'll begin to see the pile shrinking before your very eyes.

Hide other areas. Drape a plain sheet over the piles you're not currently working on. This will minimize the visual impact that might otherwise make you feel overwhelmed, and help you focus solely on the area to be worked on.

Work in small chunks of time. Choose a short period of time (15 to 30 minutes) to chip away at your stacks and help make this dreaded task more tolerable. You might try the Pomodoro Technique to help you hang in there. Of course, if you find you want to keep going once you're in the groove, by all means do so. Inch by inch really is a cinch.

Make it fun. Yes, you read that correctly - fun! Play energizing music; play Beat the Clock (see how many inches you can dwindle the pile in 15 minutes); measure your progress by weighing your discard bag after each session and try to beat the prior sessions' weight (thanks to one of my clients for this tip). Be creative and enjoy the process.