I found this piece of paper while looking for something else.
To keep myself awake and to refrain boredom from taking over me, I doodle or sketch. This was done last year, in class. These are 3 students. Because it was Aesthetics class, they were constantly moving around, hence the rushed drawing and harsh lines. As you can tell from the red ink, I was marking prior to the sketching.
Not my best, but definitely commendable, since I was half awake and bored to death.