I've used a Kaiser wooden hanger but you could use cardboard for this.
You could also vary the shape to suit your needs.
I will let the pictures do the talking.........
Don't forget to sand around the edges to make your cutting edges smoother.
So for around 15 minutes of fun, you can have your own door hanger.
Maybe you could do one with your child's name to help Santa find them and hang it on their bedroom door.