Work in the shade. If you sit in the hot sun, it will bake that nail polish so fast, you won't be able to spread it fast enough + will be left with some hideous lumps.
Have some polish remover handy to erase any mistakes or for touch ups.
*It took me 3 heavy coats to reach my desired coverage with a 1/2 hour of dry time inbetween. It might take you less or more - depending on polish + shoes.
*It is also a good idea to finish/seal in the polish with a clear spray coat or clear nail polish.