A fun option is to use wet-erase markers and let guests decorate their own glasses.
Decorate Your Glasses
If you’re throwing a big wine party and need a way for guests to keep trackof their glasses, the traditional method is to use wine glass charms. They look a lot alike (particularly after a couple of glasses), and men often find them too jewelry-like. A fun option is to use wet-erase markers and let guests decorate their own glasses. Some will just write their initials. Others will go all-out, drawing vines, grapes, cartoons, and even wine glasses on their wine glasses. It kicks of the party with some fun and lets everybody really make their glass their own. It also saves a lot of money. One set of markers will last for many parties without having to buy box after box of charms. The wet erase markers wipe off cleanly and easily with a single swipe of a damp cloth. (Thanks, Erika, for pointing out the omission.)