I'm pretty sure I don't. I think about making each letter well. It should be legible and well-proportioned, fit the style, and be the right letter--but I don't know what the perfect letter looks like.
I also don't know whether the two different approaches lead to different outcomes, though I expect I get more variation (hopefullly harmless and interesting) than she does.
Anyway, when you guys are working on something skilled, do you aim for perfection or excellence or what?