I’m a true believer that imagination is the limit. But to mention a few ideas I’ve seen out there: Egg carton for the cotton boll base, Cardstock or paper craft in brown shades, Pipe wires for the branches, Regular wire wrapped in florist tape for branches, and others. I mean anything goes depending on the look you are looking for. In my case I was looking for the most realistic look, so I found this one to be the closest. I’m sure it could still be even more realistic but I’m happy with how mine turned out.