Quickly became obsessed with this Kollabora project by Clemence of Oh The Lovely Things. You can find the tutorial here!
I used enamel paint as a base since my blue nailpolish wasn't extremely dark...and I was worried about it chipping (it's really cheap polish). I used back enamel paint, blue metalic nail polish, red nail polish, champagne nail polish, and silver glitter nailpolish. Then, of course, I added a top coat of clear nail polish and 2 coats of satin UV acrylic varnish (see my supplies!)