Treatment for dry skin:
Avoid harsh irritating soaps and lotions.
Use a cleansing bar just where one is dirty - hands, groin, axilla.
Have a soak in the tub daily (not too hot).
After soak use a moisturizer applied to the skin while the skin is moist to hold the moisture in.
A simple formula is to mix petroleum jelly 50-50 with an inexpensive cream. (Creams or lotions are usually too light to hold moisture in effectively on their own and petroleum jelly by itself is often too greasy).