Start by looking in a full-length mirror and use a handheld mirror as well. Then check each part of your body for rapid changes in color, size, shape or border of growths. Start at your scalp and move to your toes, using both mirrors. The American Academy of Dermatology has instructions on its website. They recommend that you do these checks every six to eight weeks. Dermatologists recommend annual skin exams for adults, especially if you've had significant sun damage, tanning bed use or a family history of melanoma. Self-checks should not replace your yearly exam by a dermatologist.