Teaching Tai Chi

I have learned more about teaching Tai Chi from reading the following book by Dr. Paul Lam and Maureen Miller:

Teaching Tai Chi Effectively.  By Paul Lam, M.D. and Maureen Miller.  Tai Chi Productions, Narwee, Australia, 2nd Edition, 2011.  Index, 225 pages.  ISBN: 098035739X.  "Simple and Proven Methods to Make Tai Chi Accessible to Everyone."  VSCL.  

One challenge I face when teaching at the fitness center is that I have complete beginners, intermediate students, and advanced students all attending the same two classes together.  I teach too quickly for the beginners, and get into too much step-by-step detail for the advanced students.  I need to figure out a better way of dealing with this challenge.  
I need to be silent more often.  Students are really not interested in stories and facts about the history of Tai Chi.  I ramble a bit much.  
I've been better about giving more breaks to allow students to rest and get a drink.  
I'll ask for input and questions from my students more often.