I started with something that I thought I would succeed at. In my backyard, on a hot day, I worked on drawing a pot on the end of a bench. The bench is very weathered, with many subtle colors and two patches of lichen. I tried. I am not happy with the way the shadow cast by the pot came out. I have not finished with this. This is not an ambitious attempt. The lines are simple. I thought beginning with a subject with easy-to-measure proportions would be best.
I had computer resistance to loading my drawings, so I will just talk about them. Difficult. The good things that I did: I got all the elements in terms of the right # of lobes on Columbine leaves. However, the beginning points, which were meant to be in the same place as the ending points, never met. My sense of proportion seems to change the closer I get to the ending point. Next time I will succeed at downloading my drawings.