Store jewelry in a dark, dry location. An air-tight container is the best option, and as far away from moisture as possible (not next to your shower!). A tightly sealed jewelry box, ideally lined with felt, with individual compartments allows you to arrange your jewelry so they don’t touch one another. The felt helps to absorb excess moisture and prevent premature tarnishing. Another plus side of using a jewelry box is that it also protects your collection from dust, debris, and in some cases, humidity.
Oxygen, moisture, and other chemicals are what lead to tarnished and dull metals. Minimizing exposure to lotions, perfumes, sweat, and water, as well as cleaning your jewelry after every wear, will also help to protect the metal finish. Anti-tarnish bags or strips are also useful, and they are available at mass merchants online.
If you’re not going to be wearing a piece for a while, don’t leave it sitting out. A small Ziploc bag works wonders!