Surprisingly, eBay has a good howto guide on how to size rings.  (Here’s another PDF version) Know what size ring you need before you shop so you can buy perfectly-fitting jewelry every time. To determine ring size, you can place a ring that fits you on a professional rin ...

If you happen to have 24 karat gold rings, which is often the case if you live in Asian countries, you might want to consider getting a plastic ring guard to protect your ring when you are not wearing it. These Clear, Soft Plastic Ring Guards Have a Slit in Them to Attach to You ...