As I can't find the original materials used in that link, I had to innovate ....
1) Branches and secondary branches .... from a sweeping broom with natural fibles (cheap).
2) Tree trunk ....... Green plastic covered iron "garden wire" 1mm OD is good, 2mm OD is OK.
3) Overal colour paint ..... dark brown or dark green Automotive acryllic spray cans of paint.
4) Adhesive ..... Spray can of matt Acryllic lacquer (best) or cheap hairspray.
5) 1/2 inch wide masking tape.