Skilled instructors must know essential teaching practices such as classroom management techniques, effective methods of instructional delivery, and how to provide valuable feedback on students' work. Regardless of whether teachers are teaching a small group of students or standing before a packed lecture hall, teachers always need to be mindful of how they look and sound to their audience. Teaching an online class demands a different set of skills than teaching on campus. If teachers are teaching a course that was developed by someone else, they should read or watch all of the lectures so that they know what the students have learned through these resources. When teachers practice "two-way teaching," they not only expect that students will learn what they have to teach, but also remain open to the possibility that students may have something of value to teach them in return.