Day four. I think this is generally as far as I get in trying to learn art. I hit a block where the book says "this is easy!" and it's not, or I get to the point I don't understand and I just stop.
Stupid telling people about doing a 100days challenge. I read the book, which is telling me now I'm getting into really hard stuff of midtones. Great.
I let myself just play with the midtone shading exercise, following the instructions up to I got frustrated, and then just letting myself draw. Blending with a fingertip. It's not a great result, but it's a result.
Thinking it might be time to reverse back in the book a bit and retry earlier exercises again to see how they go after getting this far in the book. Like giving your players a DC5 lockpick they struggled with at 1st level to them again at 10th for them to enjoy the difference.