When done right these look great. China glaze cracks really well and they have a nice range of Colors. I work at a beauty supply and the reviews are coming in top notch.
Instructions and the trick:
1. Apply base coat
2. Apply regular nail polish in the color of your choice as a base COLOR. Wait for it to dry well.
3. Apply your crackle color on top in a thin coat. Apply fast in about 2 sweeping strokes as this polish dries fast (hence the reason it cracks)
4. Wait for it to dry 3-5 minutes before applying the top coat.
5. Voila! Now admire your handy work :-)