I have two different types of classes.. One is lecture(where there is too much talking going on) and the other is lab (do practical things)..
During lecture, I tend to day dream and think of other things that is enjoying..
Sometimes, I sleep in my chair until my prof notices me
But I always do my assignments from other subjects.. Procrastination
During lab, I just go outside and take my smoking session.. (then go eat my snacks)
It's the only part when we're allowed to go outside and take a break.. Favorite part
Or I wear my head phones and listen to my music..