Always read instructions; they vary from product to product. Also, follow these expert tips.
• Cleanse and shave. Use a body cleanser with salicylic acid, alpha hydroxy acid, or urea (up to 20 percent). Those ingredients will help remove any dead skin. If you don’t exfoliate first, said the dermatologist Amy Newburger, M.D., “the product will appear darker in areas with more dead skin, such as knees and elbows.” It’s also a good idea to shave your legs—but be sure to do it the day before, or any little nicks or cuts will let the chemicals sink into your skin.
• Lube up. Before spraying on the self-tanner, apply body lotion all over, especially on your elbows, knees, and anyplace you have age spots, which might wind up looking even darker. Also dab some body lotion on your fingernails to avoid staining.
• Open a window. Spray at arm’s length in a well-ventilated area, slowly and continuously. To make sure you don’t inhale the mist, hold your breath or use nose plugs. If you’re using a lotion, wear gloves.
• Start at the top of your body. Then work your way down. Apply sparingly around your joints. Do the backs of your hands last.
• Skip your face if you're using a spray. You don’t want to risk inhaling it. Also, Newburger says, self-tanners might make your pores look bigger and darker (almost like blackheads). So you’re better off using a bronzing makeup on your face instead.
• Let it dry before getting dressed. “Plan to stay home for a few hours, and don’t sweat,” Newburger said, because it could cause the product to run or streak, and possibly stain your clothes. (We didn’t test for that.)