Great job Aleric. I would add,
30. Keep ac voltage and dc voltages seperate, not even running in the same duct.
31. AC at the top of the panel, dc and low voltages below that.
32. Power in at the top of devices such as fuses and relays, out at the bottom, when possible.
33. It is hard to have too many fuses, especially on AC, they isolate a problem when it occurs when correctly sized.
34. All ground wires originate form a single point, Aleric's #10. More than one ground point, especially when using Servos and Inverters causes small ghost currents in the ground loops.
35. Use 30 degree standoffs for din rails where necessary.
36. Screw din rails to the backpanel, no shortcuts with double-sided tape. It will not hold up to the heat.
38. Use a good brand of terminals, such as Wago or Altech. There are lots of great brands, but decide what you want to use and stick with the brand. They can be a major investment in just the numbers and letters that go on them and one brand does not interchange with another. They can also decrease wiring time.