The way mine turned out reminded me a bit of saran wrap nails.
I started out this manicure with two coats of Sally Hansen Insta-Dri Sea Breeze.
Then you get a cup of water and put in a couple drops of your second polish. I chose Essie Mint Candy Apple for my nails. It should spread out in the water.
To get the marbled effect you have to spray the polish with an alcohol based solution like hairspray or hand sanitizer. I spent a couple minutes trying to spray my polish with hairspray until I realized my hairspray was alcohol free...
So I ended up just spraying it with alcohol!
This technique reminded me a lot of water marbling. Except it was a lot easier for me to do!
I definitely want to try this technique again and see if I can get larger voids in my second polish.