They avoid paternalism. They listen to their teachers. In their schools, the responsibilities they assign teachers reflect teacher's professional status and their primary mission of facilitating student learning. Value their teachers as leaders. When they ask teachers for input, they actually use that input to make real changes.
Real principals give their teachers business cards.
They encourage teachers to explore their own areas of strength as leaders, whether they prefer to be community leaders, school leaders, classroom leaders, or all three. They encourage their teachers to take risks without fear of penalty for failure. Value themselves as the professional leaders they are. They deal consistently and fairly with students, parents, and teachers. They understand that real principals make mistakes, and they are honest with themselves about their strengths about areas for improvement.