We've posted a number of tips from Macrene Alexiades-Armenakas, the New York-based dermatologist with a BA, MD, and PhD from Harvard. Why? Well, she's brilliant, and she has a unique scientific and clinical background that makes her a master at identifying and evaluating the effect of active molecules on aging skin. Recently, she pointed out to us that improper cleansing methods and products can cause unnecessary harm to skin: she often sees her patients over wash, over scrub, and over dry their faces in that single skincare step. Read on so that you don't make the same mistakes.