I recently watched xSparkage's makeup room tour (which is amazing by the way) and she had the most amazing nail polish shelves with unique features. These shelves had a step up on each shelf to hold twice as much polish. They were also very well put together and solid, unlike the acrylic shelves that many people have. These particular shelves were $150 a pop. I was not convinced that I needed to pay that much, so I had my dad build custom shelves. My design has seven shelves instead of six and a cute little railing suspended on each level.
Sephora also had some great deals on nail polish recently. They had a promo of 20% off of all sale items. So I bought three different nail polish value sets.