This is a modern take on vintage half moon nails using folder binder stickers. Grab one, cut it in half, pop it on your nail, paint over it and whip it off! Easy peasy!
Just don't let it dry too much or it will take your polish off with the sticker. A thick one coat is best then take that sticker off straight away. If you do mess up, you have the beauty of a bare nail under the red so you can get your nail polish remover pen or paint brush and fix up the half moons.