Being a delicate instrument, it’s important that your cello is stored well even whether you’re leaving it for a minute or a decade.
When you need to temporarily set it aside, don’t lean it up against a chair or wall – push the endpin back in and set the instrument on its side close to a chair or other piece of furniture so that if it is bumped it will not fully fall over.
When storing the cello for any extended length of time, loosen the tension on the bow and put both in the case – preferably the hard one. Be sure to lightly loosen the strings if you are going to be storing it for longer than a few weeks. If you use a soft case, insert a PVC pipe in the bow holder to give the bow extra protection. However, if your cello is in a location free of pets, children, or clumsy humans, you may want to minimize how often you put it in or out of the case to reduce the risk of scratching.
Keep your cello in a room that has a moderate climate and away from drafts, direct sunlight, or anything that exposes it to varying temperatures or low or high humidity.