First, measure the wrist circumference, which will tell you the ideal size of the bracelet. Don't have a tailor's tape on hand? Never mind, cut a strip of paper, wrap it around your wrist and mark its circumference with a pencil. You can then easily measure the length with a classic ruler. Instead of paper, a piece of string will serve similarly. If you buy a bracelet as a gift, the recipient's watch, for example, will help to measure the wrist circumference.