So that was my actual first attempt. I got a little ahead of myself and forgot to tape off my fingers before dipping my index and middle together, so I got a big mess on my skin. I did my ring finger the proper way, then decided I really didn't like the colors. I had basically just picked a few from my collection that I found worked and spread well, but altogether over the white base coat it was too Barbie-ish for my tastes, so I cleaned them off and started over. Here's what I ended up with:
I'm happy with the final result, but I still have a LOT of practicing to do. The dots I added on afterwards were not just for decoration, but also to help disguise imperfections. Plus I got some of my white base coat showing along the edge at my cuticles for some reason. If anyone reading this has also struggled with marbling, here's a few things I learned that might help you: 1) When you drag your lines from the outside of the bullseye toward the middle, don't start with the first color of polish you dropped. Move a few rings in to where the polish starts to look solid and still wet. The outermost rings will be too thin and dry. 2) Wear an old shirt, cover your clothes, or paint naked. I got a little overzealous when trying to drop my polish colors quickly and flicked pink polish on my shirt. 3) Use a small cup. I did these with a plastic solo cup, but I've since bought a pack of small paper cups to use instead. Smaller cup = less polish wasted. And on that note, keep in mind that this technique uses a LOT of polish. I saw an obvious decrease in the fill lines of all the bottles I used. So you may not want to use your $18 indie polishes or whatever.
Polishes used: Essie Peach Daiquiri and Da Bush, Orly Smoked Out, and Zoya Tinsley