First assignment in art school, 2-D design class, back in the day (1976):
1. Crumple up a piece of aluminum foil.
2. Render it in pencil.
A maddening task, but that wasn't the end of it. The next phase of the assignment was to duplicate the drawing in ink, using a ruling pen, t-square and triangle (ah, the good old days), in parallel lines only, bringing them closer together or farther apart to indicate shading. The teacher evaluated the work by comparing the two renderings. The goal was to not be able to tell them apart when viewing them from a distance.
It was not an assignment I repeated when I became a teacher.