The most reliable way to measure ring size at home is to take a ring that already fits the correct finger and measure its inside diameter against a printed size chart. If there is no existing ring, wrap a thin strip of paper around the base of the finger, mark where...
Most jewelry buying mistakes come down to four things: not knowing what the metal actually is, not asking what has been done to the stone, buying a design that cannot be altered later, and leading with size instead of quality. Each one is easy to avoid once you know...