Forget lingerie, if you want to increase your chance of having an orgasm, keep your socks on during sex, says research done by The University of Groningen. No one is sure exactly why this works but one theory is that in order to orgasm, you need to be totally relaxed and anxiety-free, and cold feet can interfere with the ability to really get into sex, especially for women, says Fran Walfish, Ph.D, psychotherapist and author.