I'm on a committee that will require me to miss the last Friday of each month from work, which means I won't be in class tomorrow. I've lined up a pretty good substitute and left her detailed plans, which she seems eager to follow.
My three stats classes have a review assignment in preparation for next Tuesday's test. My two pre-calculus classes have a test; I'm giving my answer key to my substitute, and since she's pretty good with math, she'll at a minimum be able to use it to help students work through the 8 problems on their test. The plan for both courses is for the students to move forward, to accomplish something of value, and for the substitute teacher to have something to do.
I've never been a substitute except for having to cover someone's class on my prep period when that someone is absent, but I can't stand not having anything to do. Babysitting or herding cats, neither is for me. Having a mission, one that moves the class forward in the teacher's absence, that seems to me to make for a more interesting day.
I know a couple readers have been substitute teachers; what do you prefer?
Update 10/1/16: Ugh. My sub cancelled on me with no notice. Other substitutes on campus had to cover my classes on what would have been their prep periods. "The show must go on", so I left my meeting at the beginning of each period in order to ensure my classes, especially the ones taking tests, got started correctly and immediately.