I wish I hadn't started outlining him. Oh well.
Exercise 16: Right-Angle Study
"During the first half of the pose, draw, not what you see, but what you think you would see if you were sitting at the left side of the model instead of in front of him. [...] Of course you will not always have a front view of the model for this exercise [...] but the principle remains the same."
This one was pretty fun. Reminded me of Exercise 11: Reverse Poses.
Original (colored) pictures copyright Posemaniacs.com.