Nice I almost finished recoloring these clouds. It took a lot longer than expected but I'm happy with the results. I need to figure out how to draw these quicker in a more realistic style.

I usually started with the mid tones if there were 3 tones total, added highlights, and finally the shadows. I started with the darker tones when working with 2 tones. I think this is the most optimal method thus far.
As for the shapes, I need to write more notes to quantify the concepts into words.