Incredibly, I was able to make significant progress on the elephant drawing this week, to the point where the first two individuals are essentially complete. I am saving the feet for later because I want to add foreground, probably some shallow water. I am guessing it took about four hours of work to reach this point, which is actually pretty fast for this size. I assume that is because I'm working with skin instead of fur.
I put down a light layer of 4B charcoal, thicker in the darker areas, then blend with the tortillon. Then I blend with the chamois to smooth out the marks, and repeat with more 4B and 6B until the right values are reached. Then I added wrinkles with a light 4B line and a highlight with the kneaded eraser.
There are three more elephants after these, and I will keep posting my progress.