When couples come in to pick up their rings, I often hear them say that they don't plan on ever taking them off again. However, we recommend taking your ring off at least every night. This is especially true of wider bands and tighter fitting rings. The reason is that the skin under your ring needs air to stay healthy. If you don't take your ring off regularly, the skin can start to turn white (like when you wear a band-aid for a while), then eventually turn red and peel. A lot of people think this is an allergy to the metal, but often it's actually caused by moisture being trapped under the ring.
Another reason to take your ring off every night is to prevent it from getting stuck on your finger. Fingers tend to swell quite a bit while you sleep (and when you fly in a plane), and wearing a ring can cut off circulation. If a ring is a little on the tight side, wearing it when you sleep is when it would most likely get stuck. Also, if you never take your ring off, you may not notice if your ring size has changed. By taking it off regularly, you are more likely to notice if your finger has gotten bigger, allowing you the opportunity to get your ring re-sized before it becomes too small. I hear stories all the time from couples who have a parent that didn't take their wedding ring off for 30 years and eventually had to have the ring cut off because it no longer fit properly.
You'll also want to take your ring off when you are doing anything that could damage the ring or your hand, like moving furniture, rock climbing, lifting weights, gardening, etc. And always take your ring off before going swimming. This is the most common way that people lose their rings. Besides the risk of losing it in the water, chlorine is corrosive to gold, so you never want to wear it in a swimming pool or hot tub.
This said I don't recommend taking your ring off to wash your hands in a public bathroom. It's very common for people to lose their ring that way. They take it off and put it on the side of the sink, then it either falls into the drain, or they forget it and leave it on the side of the sink. Just wash your hands with the ring on, then slide it forward to dry your finger under the ring, then push it back into place.
When you do take it off, you'll want to have a safe place to store it whenever it's not on your finger. A ring dish or box on the nightstand or dresser is an excellent place to keep your ring. That way, you can get in the habit of putting it there each night when you take it off. And, if you need to take it off for other reasons, you will have a place where it lives.
These ring holder necklaces are also great for storing your ring when you need to take it off when you are out in the world. With these, you can easily slip the ring onto the necklace without having to remove the chain. They are perfect for temporarily storing your ring while doing things like baking or flying on a plane.