I teach MOA, Medical office Administration, while teaching I begin with a PPT presentation and I am standing in front of the class. We see a few slides then I turn off the PPT presentation and begin the discussion by throwing out a question to see who bites or I direct my question to a specific student at this point, I move around the room and sometimes lean against a desk around the students.
I feel it gives them comfort and they open up to the discussion or Q & A. This seems to work for me with my current students.