Trim the top.
Credit: Photograph by Jeremy Berger

Pull the hair on top straight up and cut into it. Start by cutting a centimeter and then continue from there. We found that even small cuts were surprisingly noticeable, so don't be too bold at first. "People are going to forgive you if you have little spots on the side of your head," Atkin says, "but if the top of your hair is screwed up, you're in trouble."