Keep handling of the coin itself to the bare minimum. Dust, scratches, fingerprints and moisture will affect the quality of your coins and depreciate their value. 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.

It is usually not a good idea to clean coins, so if it has to be done, the process should be entrusted to an expert. Collectors might actually value the patina a coin has gradually developed, and consider a cleaned coin less desirable.

Fingerprints and dust aren't the only culprits in compromising your coin collection; moisture can damage rare coins over the long run, so make sure the holder you choose protects against it. There are other protectors in the market that can do a better job and guard against moisture than the typical stapled or taped packets, which don’t provide the maximum protection. Avoid any storage space that is damp and cool when selecting a storage area for your collectible coins.