Wilson: Final, Plus

Wilson, 11" x 16", watercolor on paper

Been a long time since I posted one of those lessons in the "Learn Art in One Year" book, and I could learn a thing or two today, so......
Proportion: the relationship of the various elements in an object to the whole. In drawing, one should make sure that the ratio of all the dimensions and of the angles between each element are as close to the original model as possible. Practice. Observation. Measurement.
I may have condensed it a little, but that's the gist of it.