Why it’s hot: “Skin is a powerful mechanism of arousal,” says Fisher. A huge part of the brain is devoted to touch, she says, but less is more—once again. “Women will get hot and bothered by even the slightest caress.”How to activate it: Here’s Goddard’s tip: Let her feel your breath against her skin without touching it. When she’s not expecting it, lightly touch her skin—with a fingernail, a long, slow stroke with one finger, or your tongue—down her belly, her thigh, her back, or her ass. Some women may respond to grabbing, kneading, or smacking too, but make sure you know she’s into that before you try it out.