Reputable stands and cases are the go. The manufacturer will testify - just ask. And, you need to know, sunshine is not your friend if you're basking your nitro in it. Remember though, there's not much you can do to stop the aging process. Just accept it. Everyone here's talking good sense. Making a meal of your finish can actually add value and can liberate you, set you at ease (though this makes little sense to me as I like unfettered finishes).
Still, it's true, if you're looking to extend the life of a finish there are things you can do to slow down the aging process. Rapid temperature change is a genuine threat. Guard against it. So too is any fluctuation in relative humidity. As has already been said, you can always cover suspect materials in a more nitro-friendly material, like cotton, or play it safe and turf 'em in favor of something guaranteed to keep the gunge gremlins at bay.