Locate each name on the roster and make a point of learning student names. Let your students know that you are organized. Prepare for predictable enrollment problems and procedures. If the course or section is full and students ask to be added on an overload basis, consult with your department about its policy. Briefly sketch the kind of material presented in your class and the kinds of activities required of them throughout the semester to give students an idea of what to expect from your course.
Enthusiasm comes from confidence, excitement about the subject, and pleasure in teaching.
Your facial expressions and smiles, attentiveness to students, movement away from the podium or chalkboard, and eye contact which is long enough to observe students' expressions will all demonstrate your enthusiasm. Finally, ask if there are any questions regarding the course, its requirements, or your role within it. Be sure to pause long enough for the students to reflect and formulate questions.