Start using one of these (if you haven't already)

Our posts have been a lot about hand care lately, but since you only have 2 and need them badly during a wod, the least you can to is take proper care of them.
Already a big fan of Ript Skin Systems & Climb On!, we still wanted to share another useful tool with you.
Officially not meant for use on hands, using a callus shaver is actually a great way to remove thick calluses on  your hands, although some caution is required. Seriously, look at the thing. It's scary.

Basically, it works the same as a cheese slicer, Put the sharp part on the callus, apply a small bit of pressure and pull. Did you pay attention? A small bit of pressure!
The blade is friggin' sharp, they might as well have used a callus shaver to film this scene.
So just run it carefully, especially if you don't have very thick calluses.
Where to buy? Pretty much any drugstore should sell these, or pick 'em up online here:

Amazon.com
Walgreens

Tweezerman Comfort Callus Shaver Rasp Model 5085R $ 12