A bridal garter can be worn on the left or right leg. There are no traditions that state the garter should be worn on a certain leg. It is up to the bride to make this decision.
The bride typically chooses to wear the garter on the leg she crosses over the other most often. It is frequently on her dominating side. A bride that is left-handed often chooses to wear the garter on her left leg. Most brides wear two garters on their wedding day, which include the main garter and the one that is tossed during the reception. Both garters are worn on the same leg. The main garter goes on first, as it is sits higher on the leg than the tossing garter.