Avoid touching your coins as much as possible. The condition of collectible coins impacts the value: dirty, scratched, moisture-damaged or otherwise imperfect coins can result from too much handling. Refrain from direct contact with your coins, especially mint condition ones, but necessary handling should always be done by only touching the rim of the coin and never the center.

Cleaning coins is not recommended and if necessary should be left to an expert. A coin's patina, gradually developed over a period of time, might increase the coin's desirability, whereas cleaning the coin could make it less valuable.

Fingerprints and dust aren't the only culprits in compromising your coin collection; moisture can damage mercury dimes over the long run, so make sure the holder you choose protects against it. Typical stapled or taped packets do not provide the optimum amount of protection, however there are other protectors available that can also protect against moisture. When selecting a storage space for your collectible coins, make sure they are not in an area given to dampness, such as a cellar or basement.