This was tough, but I did my best.

I messed up the notan version a bit, but no big deal.

Ugh. My proportions are off yet again.

I did my best here. I tried to choose shadows and halftones that weren't super-obvious, to make this more of a challenge. I may have bitten off more than I can chew.

I decided to challenge myself and do this in graphite. It's clear that it got away from me pretty early on (stupid proportions!), but this is actually much better than I expected. I'll probably take another try at it.

4B and 2H. Took just under an hour. Lots of adjusting!

2B(I think) and 2H. Took a little over an hour.

Complex AO study of my son's toy.

Well, here's my first attempt at this. I wasn't sure if I should draw directly on the images, because they already have shadows. Just in case, I drew mine from scratch.

This was tough.

The angles I drew from and the angles of the photos are a little bit off. Also, I just had a bit of trouble drawing in the dark. In any case, I think I got the terminators and cast shadows identified correctly.

I'm in!

Looking at some of the other assignments, I now think I should have varied my backgrounds more.

Now I'm wondering if it might be worth it to take a break from this to try Dorian Iten's Shading Course you mentioned and come back after it. My shading is currently only okay at best.

Second try! I feel a lot better about this one compared to my last attempt.

Well, I think I did alright for a first attempt. I'll probably try this again, taking more time to check proportions, among other things. I only used the hard round brush for this.