The rule of thumb with all media storage is cool, dry, and clean with minimal light exposure. However, like film, an overly dry environment can cause tape to become brittle. Generally though storage within a home or office offers humidity levels that are fine.
Videotapes use magnetic recording technology so it is important to store tapes away from any type of strong electromagnetic fields. For example, speakers generate an electromagnetic field and tapes should be stored away from them. Strong electromagnetic fields can damage and even erase footage on tapes.
If you’re able to, take a cue from the past and, “Be Kind, Please Rewind” when storing or relocating videotapes. When not rewound, it can cause sagging and ultimately damage to the actual tape.
Finally, for long-term storage it is best to store your tapes upright. For those who remember, think of how video rental stores had them on shelves. The idea being that storing them in a flat position causes a gradual pull on the reels that can damage the actual tape.