Besides the wings and halo, this costume requires practically no effort. Just throw together an all-white outfit and liberally spread glitter on your kid's face and hair. Use white or sparkly pipe cleaners to make the halo. You might need to twirl two together in order to make it stand up. Cover the hangers in cotton, and hook them together (it should look like butterfly wings). Then use string to loop the hangers over your kid's shoulders.