Avoid storing spices over a stove. Warm temperatures cause seasonings to prematurely release their essential oils and flavors.
Store your products in a dark cabinet — not the humid fridge. Light fades spices, and moisture causes them to deteriorate and mold.
Read expiration dates, and toss spices that are older than a year. Old spices impart significantly less flavor.
Buy bottled for frequently used spices, and pick up smaller quantities of bulk to try something new. Bottled seasonings, which have limited exposure to light or air, sometimes pack more punch than bulk products.
Try grinding whole peppercorns, nutmeg, and cumin in a coffee grinder. Process a bit of white rice or bread in grinder before and after to soak up unwanted flavors and oils.