The Skincare Sins And Secrets Of A Celebrity Esthetician

We all have a list of skincare sins: those bad habits we've been trying to break for years. All of us except professional, licensed estheticians, that is. They're always following the rules, right? Wrong. Celebrity esthetician Renée Rouleau—who opened her first skincare spa at 21 and works with clients like Emmy Rossum, Demi Lovato, and Emma Roberts—div…