3. Falling Asleep On Door Duty
This one might sound stupid, but it could not be more important. In film school especially, but also on a real gig there are these lowly people on production sets that are just getting started in their careers called production assistants. They help everyone who needs help and often take care of silly tasks like making coffee in the mornings. They can also be placed as guards to ward off people who would walk through a set and ruin the director's shot, which in some cases can be extremely serious. Sometimes these poor, hapless PA's are left at their guard posts for so long that they begin to drift off. If you ever find yourself in this position don't let it happen. At film school falling asleep while watching the door is the same as a Japanese samurai who brings disgrace upon his family's honor. In other words people have a tendency to frown upon it.