With my wifes feet, hers get really dry as well. Here heels especially would get so dry that her heels would literally crack and bleed and take forever to heal (no pun intended).
We were told that the neuropathy causes it and to keep lotion on them daily or twice a day or whatever it takes.
BUT, we were also told when you put lotion on your feet, NEVER, get it in between the toes!
It can cause a fungus to start even worse and lead to serious complications. I lotion my wifes feet twice a day, and I make sure to wipe in between her toes with a soft cloth when I am done just to make sure that it is clean in those places.
It seems to work for her. I use the pink bottle of Olay - Active Hydrationg fluid...and it seems to work well...for my wife that is.

Hope this will help some. Of course yours may be something completely different, but you might try it and see if it works for you.