Some common bad practices that school principals follow

1. Not including teachers in the decision making process. Decisions made from “on high” can seem gratuitous or arbitrary.
2. Not backing up teachers in tough situations. It’s very important for teachers to know that they will be supported if they make a decision that will upset a parent.
3. Punishing teachers instead of helping them improve. Teachers are human beings - they make mistakes and have failings. Helping teachers improve is far better than punishing them with bad schedules, room relocations, or layoffs.
4. Sitting in the office instead of roaming the building. Teachers and students should see the principal on a regular basis around the school.
5. Making everything a priority. When everything is your priority, nothing is your priority.
6. Ignoring major problems. We all know that not every problem can be solved. But you can always make an attempt.
7. Appeasing parents when they are being unreasonable. Giving parents what they request when it doesn’t impair the education process makes sense. But when it does? Not so much.
8. Allowing favoritism to continue. This is very common for coaches, athletes, and “principal’s favorite” teachers.
9. Promising but not delivering. If you’re not sure a thing can be done, don’t promise it.
10. Not putting academics first. Schools have to be a school first, and everything else second.

There are many more, but I’ve seen these failings committed over and over again.