I put each structure on a different layer and gave it a different color. They're pretty funny looking but they helped sort some things out. I have a tendency to skip over things when I've got a pencil in my hand. I tell myself to be disciplined about it, but inevitably, at some point, my intuition insists it knows where the line is supposed to go and I don't bother measuring. Working digitally in this way, my intuition admits it doesn't know what to do, I have to measure.