There are a few things to consider when storing your coins that will help keep them in the best quality condition as well as safe.
1. You will want to make sure that you keep your coins stored in a place that is cool and dry. If coins are stored in a place that has moisture or spikes in temperature your coins are likely to get tarnished and develop spots. Such places might include an attic or a basement so avoid these two areas at all cost. If your coins do get tarnished, spots, scratches etc. it will dramatically affect their value.
2. When you receive the coins that you purchased be sure and leave them in their original sealed casing. All proof and commemorative coins should be purchased and sold in their casing or capsules that they originally came in. Leaving them in their casing will also ensure that your coins maintain a better quality then if you were to remove them.
3. When purchasing coins that are proof, commemorative sets, or uncirculated you should receive a certificate of authenticity and an information card. You will want to hold onto these and put them in a place that you will be able to find them if you did ever decide to sell your coins. You will have an easier and better chance at selling your coins with the certificate and information card in hand.
4. You will want to store them in a safe place whether that be in a safe deposit box at a bank, a bank vault, or in your home. I would recommend storing them in your home unless you have a large stockpile, then a safe deposit box would be better. If you store your coins at a bank make sure they are registered in your name as property to you and not the banks and if you are storing them at your home you will want to make sure they are covered under your home owners insurance in case of a burglary, flood etc.
There are many different casings that coins are stored and displayed in. Some of the most popular include plastic tubes, which is generally used for roles of coins, hard plastic covers used to store more valuable coins or small sets, polyethylene sleeves are used to store coins short term, and slabs, which is a sealed plastic casing used for very valuable coins.
If you do decide to purchase coins or already have some in your possession make sure you are careful to store them in a safe place that also does not hinder the quality of the coin, which can hinder its value. Old rare gold coins for sale