Some of the causes of cracked heels are dry air, lack of moisture, improper foot care, an unhealthy diet, aging, prolonged standing on hard floors and wearing the wrong types of shoes. Conditions like eczema, psoriasis, corns and calluses, diabetes and thyroid disease may also contribute to the problem. Soak your feet in this warm soapy water for about 20 minutes. Use a pumice stone to gently scrub off the loosened dead skin cells. Rinse off your feet with clean water and pat dry with a soft towel. Apply some foot cream or moisturizer and wear a pair of clean cotton socks overnight. Repeat this daily until you get the desired soft skin.