Here are pix of how I store my nail polishes. It is not a large collection at all but they have to go somewhere! I purchase this tiered plastic tray at The Container Store. It was in the kitchen department, I guess for cabinets or under the sink use, but it’s perfect for finding the polish I’m looking for at a glance! You can find it here. I definitely recommend walking down their aisles if you’re in an “organizing zone” and keep your eyes peeled for using something for your needs as opposed to what its meant for:)
The tray also keeps the polishes safely displayed on my shelf-with the high lip all around it that keeps them all in place. I organized them by placing currently used ones at the bottom, more springy and summery colors in the middle and my daughters’ at the top.