Swatching using Cabochons, or, I am the crazy polish lady.
Swatching your collection can be an important part of the life of the polisher. If you have more than a few polishes, especially more than a few of each color, as I have obviously ended up with, having the ability to compare colors and see what they'd look like against your skin before applying can be pretty valuable.
I tried swatching on nail wheels, just the basic ones you buy at Sally's Beauty, and while they came in handy for a while, I found that they were a little flimsy, and I ran out of room on them. I had to swatch blues on my nudes wheel, greens on my pinks wheel, etc., and it was driving me batty. I could've invested in infinite numbers of wheels, but the ability to compare would still be hampered.
Swatch sticks (fake nails attached to small wooden or plastic sticks) are also pretty popular, and I may end up doing that as well, but I got the idea (from some fabulous members of a polish thread on Something Awful) to paint all of my polishes on the backs of glass cabochons (acquired at the dollar store), then attach them to magnets and stick them to a metal surface (as of right now, a cookie sheet I got at TJ Maxx, because it's big enough and once I find a more permanent metal surface I can hang somewhere, I can bake cookies!)
For glitters, I painted the backs with 2 coats, then a coat of black, and for all other polishes, I put 2 coats on, then a coat of white to ensure opacity so the adhesive on the magnets doesn't show through the polish. I numbered the cabochons and their corresponding bottles with the same number, so I can match the cabochon with the polish I used on it; I'm hoping to have the numbers in a spreadsheet soon for quick reference. I had a heck of a good time doing this, and now have some really pretty interactive art to show me what my polishes look like!
One thing to keep in mind if you plan on doing this; don't get cabochons with any iridescence on them. It will mar the color of the polish as it shines through the glass, making your swatches inaccurate. Also, ventilate! You likely won't get bubbles in your polish like you might if you have a fan on and windows open when painting your nails, and the fumes could build up really quick.