To-Do List: Deck
After the deck area was cleared out, the first thing I did was run tape lines between the footings. Then I confirmed these lines against a drawing I'd rendered that shows all of the main structural components. An inch or two of error in footing placement would not affect the structure.
Grey circles are footings; green bars are bearing beams; orange lines are floor joists. The design is a bit more robust than it needs to be, and I like having it that way.
The deck will be quite costly to build. Consider: each footing requires a 6x6 post anchor, and each anchor is about $35. There are 21 footings, so do the math. It may be two or three years before it's done.