I get students asking me for drawings a lot. The way I manage these requests: On the last day of classes before mid-semester exams, I allow students the period to prepare an index card full of whatever materials they think they might need for the upcoming test. While they work on that, I pass around a clipboard and have them write down something they want me to draw for them. I like to joke that these quick doodles are their holiday gifts.
Teachable Moments 