I have used thick skewers and bread ties.........a tomato cage.........bamboo poles tied into a grid.........metal steaks hammered into the ground to tie down to...........lots of ways. The thick skewers was funny.........looked like Jesus!
I'd top yours a few nodes up from the bottom.......clone the top. Take the branches that form and spread them out like a open upside down umbrella. Nothing special or exact just open up for light and air.