Hey... I made them with aluminum foil (the normal stuff for the kitchen xD) and form my horn with it. When u have a basic form, just encase it with modelling clay (should be air-drying)... But attention! Just a thin layer of modelling clay or it becomes to heavy. If u searching for a really light alternative, use "Kobracast" or "Worblas Finest Art" instead of modelling clay. Both are Termoplast and very light... But expensive.