I second Donna's recommendation about the pumice stone. I keep one in my shower and a few days a week, I scrub the heck out of my soles. I also have a callus shaver that I use because I get stubborn calluses on my big toes too and when they resist the pumice stone, a few gentle shaves with the callus shaver, after a good soaking, does the trick. I also moisturize my feet nightly with shea butter or Burt's Bees Coconut Foot Cream.
Tracey
"Do or do not. There is no try." -Yoda
"Where there's a will, there's a way."