The best way is to learn for yourself-but I have found that setting the disc. right at the front of the word "foil" the small pieces will be left out and the larger ones will break up and less chance of missing small gold rings. For coins, larger rings, just take a regular nickel and set it where you just get a clear signal on the nickel. This is Jack Gifford's suggestion for a new user. The owner's manual has a good way-selecting several objects and finding out where they are eliminated. Heck, the fun of this detector is learning for yourself.