The metal ring
For the base, glue the metal ring onto the tree disc using hot glue. As long as the glue has not cooled down completely, you should support the ring. Then pluck the individual twigs from the bundle and remove the thick end.
First use the twigs to hide the glue spot on the wooden disc and then glue the ring piece by piece. At the base, the branches can go in all directions. On the ring, you should only work in one direction.