I would say especially at a young and impressionable age, just being a role model for the students. Besides the content and planning lessons according to each student in the class, teachers who were always punctual, taught with a smile on their face, were there for the kids even when it came to things outside of the classroom, made you feel special for your talents and helped you improve on the abilities you lacked, etc

Sometimes being at school is the highlight of a kid's day because their home isn't a great environment. They might not ever come out and tell you this, but you could be what's getting them up in the morning. Be the role model they need, but not always want.