My boyfriend is going as The Lich from Adventure Time for halloween this year. He found an awesome mask to modify, some skeleton gloves, and sheets/fabric at the thrift store for the clothing pieces. However, since we are on a budget and needed everything to be homemade, the horn was the most challenging part of the costume. Here's the end result of my cheap and actually relatively easy project last night:
And here's The Lich, if you've never seen Adventure Time:
We'd seen projects online that involved carving the horn out of expanding foam, using foil to make a basic shape and then use ModelMagic around it, but the expanding foam seemed like a lot of work and while the ModelMagic is probably very lightweight, neither of us make much money.
I made the horn completely out of things I had around the house:
1. thin cardboard packaging (like cereal boxes)
2. tacky glue
3. duct tape
4. painter's tape
So I'm not the best at making tutorials but here's a basic one, and if you have any questions about the process, I will try to answer them!
Step 1: Make tubes out of the cardboard using duct tape or tacky glue. These can be various sizes depending on how thick you want your horn as well as how "sharp" you want the angles of the curve to be.
Step 2: Besides the base piece of the horn, which will probably be the thickest/widest circle, you'll want to cut out a semi circle section like this. This is what makes it curve! These pieces will probably vary in thickness throughout.
Step 3: (sorry I can't be more helpful here lol) Tape the pieces together in the shape that you want. The curved part is the most difficult. You kind of have to think about the direction you want the tube to go in, and then twist the pieces around (before taping) until you get the achieved direction. When you get to the part where you want the tip to be, make tapering pieces by making a circle piece and then sort of make an "X" where the two ends of the cardboard tube piece meet before the glue dries.
Step 4: Cover the whole thing with painter's tape. You could use bondo or something like that, but I didn't have any of that but I had a big roll of painter's tape. This will give you a smoother surface. Around curves you'll want to notch part of the tape so that you can lay it flat against the curves. I also sometimes had to tape a small piece of cardboard against it when the tubes didn't line up completely.
Step 5: Paint it with a few coats of a base color. I used a light gray in Martha Stewart all purpose paint. I really like her paints - they are very good opaque paints.
Then paint it however you want with acrylic paints and add any other details you'd like.