Another really simple look. I'm really into diagonals right now... mostly because I discovered how easy they are!
To get this look, take a sea-green color and paint your whole nail. I used one of the Revlon Top Seed ones, since they dry pretty fast. Then take a dark blue and draw a fat diagonal line across your nail. Fill in the edge, but don't worry about making it too perfect. Cover with Seche Vite top coat and you're done!