DO rather than TELL . It is not what we say, but rather what we do, that others will emulate. We all learn form each other. No matter what we preach to others, it is what we do that they will do. This triggers debate, argument, discussion in class, so students ultimately are encouraged to think for themselves rather than regurgitate the opinions of others.
Students play an active role in their own learning in the classroom, rather than passive.
I have fun. If the professor enjoys the subject, and lets his enthusiasm, interest, and excitement show, then his students likely will also. Telling students that the subject is exciting does not communicate as effectively as being excited yourself. You have to believe in your students. Have high expectations.