In addition to the assignment described in the video, here is a bonus assignment;

Bonus assignment - Using the images provided from Reference Pictures (this one is a free pack, used in this course with permission), do painting studies of each image. Pay close attention to where the core shadows are, and how the fade or fall off toward the shadow sides. This might be a rigorous study, but I promise you’ll learn so much by doing this exercise. It’s not meant to create art masterpieces, only to expose you to all the nooks and crannies of things you need to know.