Girls wear garters to their proms to give to their dates as a memento of the evening. Often girls choose garters that match their dresses, sometimes customized or containing sayings commemorating the special evening.
There is some disagreement regarding whether the girl or her date is supposed to remove the garter. According to Garters.com, a girl going to prom should remove her own garter before prom begins and hand it to her date so he can wear it on his arm. Some schools even have garter removal ceremonies. However, Garter Boutique points out that in some communities, the date is expected to remove the garter either before or after the prom.