I was also afraid of the dotting! Some polishes aren't too opaque, so I thought that they wouldn't cover the other color well enough in the overlapping part. Well the polishes covered well enough, my dots were just a bit off!
I still like how it turned out though, especially for a first attempt! It was a lot easier to do than I thought it would be, and I really love the finished product.
I used Ulta Snow White first, applying two coats of it. I then free handed a line diagonally across each nail with Claire's Breakfast at Tiffany's. I figured the line didn't have to be perfect since I was going to put dots right on the edge anyway. It's also strange how green the bottle appears, but how blue the polish really is! It's like that in person.
I then took a medium sized dotting tool and began with the dots on the line. I did white first, and then filled in the rest of the greenish-blue area with white dots. I did the blue dots next, though they didn't want to cooperate as well!
I still really like how it turned out! The dots aren't perfect, but it's not too noticeable unless you stare at it for a long time. In person, it's just so overwhelming with dots that you barely notice!