Once you have finished a spiral staircase, if it is next to a wall there is no easy way to plan the next level of wall beside it, the tile border does not show up at all from all angles but standing directly above the wall.
After trying from many different angles I was finally able to plan the two walls above next to the stairs by rotating the stairs in such a manner that allowed you to walk out on top of the wall down below and then plan the new wall above it. I suggest planning the new walls before building the next level of stairs as it is easier to walk onto the wall.
There must be an easier and safer way to do this, a few levels off the ground is not bad, but having to do this from greater heights is a risk.