Show your expertise in the subject matter. It's important for your students to know that they can trust you as an expert in your field.
o When you introduce yourself, tell them how many years you've been working in your field and what you have achieved there. Then they'll know you know your stuff.
o Tell them how long you've been teaching your course. If you've been teaching the same course twenty times, let them know, so they have a sense that you've created the best course possible. If you're new to the classroom, however, don't let your students know so they don't see you as a pushover.