Witch hats are one of the easiest (and in my opinion cutest) things you can pipe for Halloween out of royal icing. The hat band is optional, but you could pipe it in any color you want to coordinate with your cupcake liners, icing, whatever. All you'll need are black stiff consistency royal icing (or another, less iconic, color), round tip #12, a flower nail, parchment paper squares, a glue stick, a Styrofoam block to rest the nail in, and a dusting pouch filled with a 50/50 mix of powdered sugar and cornstarch. If you're going to pipe a hat band, you'll want a contrasting color and an oval tip #55 (I used a #57 which was a little too large). Start by sticking a parchment square to the flower nail with a dab from the glue stick.