I position the first three pieces of rebar, setting them on top of concrete fragments, which helps them stay in place. I lay two more pieces of rebar in the opposite direction, and continue adding concrete until the hole is filled.
After the mix sets for few minutes, I screed the surface flat with a straightedge, let the water rise, and broom it off. After another few minutes, I lightly tap the surface with the straightedge, then screed it flush with the slab. In a few minutes I brush off any water that rises and let the concrete cure.
A week passes before I can install the columns. To get a fast measurement, I stack the cap and base plates together on the footing and measure up.
I prop the columns in a stable position (generally on horses, but here I used the basement stairs) and go to work with the cutter and pipe wrench.
Once the steel is cut, the concrete breaks easily. There's usually some concrete protruding that I chip away with a hammer.