So I tried these yesterday and made my own. You can make about 8 horns with one package of Fimo.
I did everything like the video said and they came out pretty good. It beats paying 8.00 bucks for 2 horns at those Halloween stores. I also tried them out and (for us) it is better to put the horns on before the make up otherwise it won't stay on. Of course I have the cheap make up and not the ones that all these professional people have been using.