Once you have chosen your wedding ring, the next thing to do is make sure the size is right to ensurthat the ring fits perfectly. The best way to determine ring size is to have a jeweler use a ring sizer (also called a finger gauge set). It consists of a series of metal rings in ½ size increments that slide onto the finger to measure it for the best fit. Leaving it to a professional takes any uncertainty out of the process. (Thanks to GIA.edu).