My shading exercise. Any feedback is welcome. Thanks.

I decided that I wasn't satisfied with doing this exercise with graphite, charcoal, pastel, and conté, so I did three more in gouache after trying a few in watercolours. The first gouache isn't quite right: the casht shadow is too large and the terminator is too high. On the second, I got better transition with the midtones. The highlight is all wrong but meh. And on the third, I'm generally happy. The watercolours were fun, but much more challenging but I started with the wrong base colour for the cast shadow anyway, so I at last just tried with black and that came out better.

Applying the lessons from the critique. Digital, but used the tools in pencil paper "mode".

thanks!

self critique on attempt #2. I had improved all three of my weaknesses on this attempt. But still way off on terminator and cast shadow

self critique on attempt #1

Anybody know what brush Stan is using here, please?

I noticed my problem is the half tones I might have to go back over the lesson this weekend. Does this apply to color cause they feel connected.