RingS

For the most accurate measurement, head to your local jeweler. If you don't have a jeweler nearby, the next best option is to find an inexpensive ring sizer on Amazon. The string and ruler method can suffice in some circumstances but isn’t the most accurate for rings.

Cuffs

Wrap a piece of string around your wrist just up from your wrist bone. This measures your wrist circumference. Subtract approximately an inch to an inch and a half to find the length of cuff you wear.