One thing I have read on many many nail polishes is the IKEA Helmer for storing polish. Well, now I too am singing it's praises. It's AWESOME!! I can't tell you how great this thing is. The polishes can all stand up, which is the best way to store them. I don't have much more to say about this that isn't just gushing praise, so I'll just show you a couple pictures and tell you that if you are able to get one you will definitely not regret it!
Ta da!! The Helmer.
Top drawer has all my China Glaze, MAC and Zoya polishes.