After playing guitar for some time, I think I've finally come up with a routine that helps keep my callouses stay in good shape.

Before my nightly and morning shower, I put liquid "new skin" on. This keeps my callouses covered with a waterproofed coating so I can
take a nice long shower without having to worry about get my fingers too soft. After I get to work the next day, I take the "new skin" off
with fingernail polish remover and use alcohol throughout the day to help toughen up the skin. Also, throughout the day, I have a guitar at the office so I can get some practice in. When I get home, I hit it hard for an hour or two of practice and the cycle begins all over again.

If some dead skin starts to peel, I resist pulling it off (risking taking too much skin off) and instead I use a fine grade of sandpaper to lightly sand the tips smooth.

This works for me and I thought it might be helpful to someone here.

Ken

Ken,
How do you apply (and how often) the alcohol "throughout the day"? Doesn't it dry up the skin (maybe that's the idea)? I agree with the fine grade sand paper if some skin starts coming off. NEVER pull on it. If too much is coming off, I snip and then sand. Thanks.

Eiko,

I apply it about 2 or 3 times a day. My callouses are as hard as leather. I think as to being too dry, I think that is what callous is--dead, hard, dry skin.

Ken