Purchase oysters from a reputable seafood seller. The fresher the better, so ask when they were harvested and avoid oysters more than 3 days old. Look for oysters that are tightly closed and displayed on ice. At home, give them a good scrub and store them over ice in the refrigerator, either in a mesh bag or loosely wrapped in a kitchen towel. Do not place them directly on the ice - the fresh water will harm the. Adapted from Yankee Magazine.