Make a good first impression. If you stroll into class late or your cell phone rings during lecture, the chances are good that you will be singled out for unfair treatment.
Speak up if you feel that you were treated unfairly. If the professor says something to you in front of the class that you feel was rude than call her on it immediately. Putting her on the spot might just fix the problem itself.
Participate in class and stay on top of your assignments. If you must challenge an unfair grade, you will have proof that you deserved better.
Treat the teacher with respect. They are all humans and make mistakes. If you feel the teacher was being unfair then talk to him about it.
Report the teacher to the dean if you feel that you are a victim of unfair treatment. Before you report a teacher to the dean make sure that your actions don't warrant the treatment you have received. Ask other students if they think you have a case.