First, pair the earrings and attach to each other.
Hoops - open one hoop. Slip the other closed hoop inside. Close hoop.
Posts - remove back from one post. Slip post through the back of the other post and slide back onto post.
Even if you take it no further, this is a sure way to keep the pairs together and it is much easier to find an attached pair than a single earring.
Next, find yourself an antique tin-type tray and place on shelf in your closet. You might find one at an antique store or flea market. Alternately, you can use shallow drawer space with dividers.
Arrange earrings by ascending size of hoops, stone earrings, pearl earrings, whatever makes sense to you. Silver on one side, gold on the other. Cover silver side with tarnish-free flannel cloth. Charms and chains behind the earrings. See an empty compartment? You should be able to guess which earrings are missing. (If you were really anal, you could label the compartment.)
Click here to organize necklaces.