Just a quick share of an interesting but usefull idea for those small branches or sturdy twigs. Why not turn them into a scarf hanger? This was an image found on Tumbler ~ no I don't use it, I have enough trouble undertanding the point ot Twitter let alone Tumbler.
I would imagine that you assemble the branch pieces in the order you want them. Then perhaps drill holes top and bottom to glue wooden dowels in (although this frame looks a bit thin for this, screws would be secure but untidy in my opinion). Perhaps another way is using a glue gun to secure them and then when the frame is fixed in place everything is secure.