Gary Huston [on you tune] actually drill the end of the rod, threads it to the bottom of the hole, then uses a screw to hold everything together.
I square the end of the rod and drive the petals with their round holes over the square rod. This prevents things from turning and peening the end down locks everything up solid.
Hate doing the final shaping and having a set of petals come loose. Those end up landing at the far end of my shop.
Pick a way and try it for several roses. If you are happy keep that way. if not, select another way and try it for a few roses.
Where are the PICS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!????????????????
Dave