I started off with 3 coats of Petites Electric Indigo. The first coat was really sheer and the polish leaves some brush strokes, but besides that it's a pretty color. I don't see why these polishes are $3.99 though because I can get drugstore polishes for much cheaper, and I can get China Glaze polishes for about $4. I wouldn't say this is worth $4....but it works for this mani.
For the clouds, I sponged on white acrylic paint using an old eyeshadow applicator. It worked perfectly because it was so small! Then I used a tiny dotting tool to make the little birdies... some of them look better than others ;)