By the end of the lesson, my model had mushy corners in the eyes. I debated how to create a quad junction on both eyes and ultimately went with two edge loops—which felt suboptimal, but I couldn't figure the junctions out.
The real kicker, though, was seeing tons of single pixel artifacts all over the render. Despite having the Multiple Importance option checked on my lights, it took the Denoise setting to remove them. (This then left that black smudge on one of the specular highlights. Not sure how to fix that.)
All in all this was another really fun exercise, and I learned a lot!
