Stick them on the walls or ceiling and fill you room with lowing moon and stars. Expose the moon and stars to a light source for a minute. Turn off the light and watch them glow. They will glow like magic in the darkness. Recharge them and they glow again and again. The fun in unlimited.
As tempting as it is to call this astral projection, that really isn't what that means. Still, you can put stars and constellations on the walls and ceiling.