Humility
The Orchot Tzaddikim spends a great deal of time emphasizing the importance of ענוה or humility. This ענוה is the key to all kinds of blessing. A person becomes a vessel towards being able to receive abundance from Hashem. When one is too full of himself, he has no place for this שפע, abundance, to enter.He further says that a true sign of humility is the ability to seek the counsel of a rabbi. One must realize that the wisdom that the rabbi possesses is coming from a high place. Especially today, when wisdom is measured by college degrees, it takes a certain degree of humility to take advise from a rabbi rather than a professional.Another example of ענוה is on the rabbi or teacher. He must have the humility and patience to explain things over and over again to students who don't understand things the first or second time. He should appreciate the student's desire to learn, and encourage him with love, patience, and humility.