Step 4: The Rebar Goes Up
Basically, you just start at the bottom and work up. The more rebar and the more tie wired intersections, the stronger the structure becomes.
I do all the wire twisting on the inside, to prevent wire snags on the topside, that interfere with stretching out the fishnet later.
If you want to put in electricity or water lines, now is the time. I decided not to. There is electricity nearby, and I have extension cords, if I ever need work light at night. There are lots of rings in the ceiling from which to suspend lights, so the situation is very flexible.