When trying to find a ring she won't miss, you need to avoid accidentally picking a ring that she doesn't wear because it doesn't fit.Jewelry Professional & Founder of Ring Concierge Expert Interview. A properly fitted ring will slide over the knuckle with only a bit of struggle, then sit snugly at the base of the finger without causing pain or tingling.Plus, you’ll need to choose a ring that she won’t notice is missing. That being said, you should be careful that the ring you choose definitely fits her well and is worn on her ring finger. This is one of the most effective ways to sneakily check her size, because you’re going off of a ring that she already wears and you’re getting the help of a professional. A jeweler can handle the sizing for you with another ring for reference.