While there are any number of earring holders for sale in retail stores, but why not get creative and make one that satisfies your specific needs. Depending on the type of earrings you typically wear there are varying solutions. This page contains some ideas for making earring holders.
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I have pierced earrings of various sizes and shapes. I keep my jewelry in a large jewelry armoire however, there's no good way to keep up with all of the sets of earrings.
Plastic ice cube trays make great organizers for rings and earrings. I have mine sorted into them and have them in one of the small plastic storage bins with shallow drawers.