First, we'll start with China Glaze Pool Party under OPI Black Shatter. This was my first experience with Black Shatter and Pool Party was the perfect neon pink to put under it. It's bright, in-your-face, and looks great in two or three coats (if you're picky). The only problem I had with the formula is that it chipped easily. It's not the end of the world to touch it up once in a while, but it is annoying. Neons are notorious for not photographing correctly, but I think I got pretty close with Pool Party.
Next up is China Glaze Flip Flop Fantasy under Cracked Concrete. I think that this is a more toned-down version of the neon and crackle combination. FFF is such a unique color, kind of peachy, kind of coral-y, but almost cloudy in appearance. It applied and wore much better than Pool Party and is perfect for a summer pedicure!
Overall, I love all of these colors and their combos, and I can't wait to get my hands on some more neons!