Making the students feel at ease is important.  Some students will probably take a little longer, some almost immediately.  Getting to know a little bit about each students helps the teacher better address the overall personality of the class/cohort.

Preparation is the key to a successful class session.  If each session is carefully planned and presented, then the course as a whole tends to be successful.  Tools like checklists are very useful.

Setting a good example is of utmost importance.  The students perceive the teacher as a role model to be emulated.  Another important aspect of professionalism is preparation.  Being ready to teach, start the lesson on time, shows professional behavior and creates a better environment in which the students absorb the material better, especially when well-prepared and presented in a logical way.

The challenge is keeping the student engaged.  It seems that attention spans are shorter in today's students, so I believe  asynchronous learning is better, but not by itself.  Asynchronous learning allows the student to review the material as many times as needed, and that is important.  It is also important to include some synchronous learning times, so finding the correct balance is something that probably could be tailored according to the general personality of all the students.

In my experience both as a teacher and as a student, visual learning is very effective.  As such, providing visual and virtual learning experiences for students helps not only for me to illustrate the material, but also, for students, provide a rich learning environment.