Fifty students in a three hundred seat lecture theater will tend to arrange themselves in randomly in groups of one two or three with lots of space between - a sort of agoraphobics' open day. Grouping the students more closely increases the energy in the class by increasing the chances of random interaction between the students. I remind myself that I have the right to do this - it is my class. Encourage heckling, wise cracks and questions but keep control. Many lecturers feel that they need status and distance to operate effectively and feel threatened or exposed by such practices, student participation is a vital part of education and things such as power dressing can prevent information flow.
Most egos wither as a result.
I make sure that my students know me as a person, I let them know my hobbies and interests endeavour to find out something about theirs. Taking a few moments to talk to different students in or out of class time is helpful, for lecturing is the most intimate form of relationship marketing. Eye contact is good for most European students, in many other cultures it is considered rude to maintain eye contact with a lecturer, in such cases a side on approach may be more successful. Similarly when students are uncertain as to what is coming next they are attentive and ready to learn. I have used renaissance art, music and history to underline major teaching points in Management Information Systems, or digressed into potted histories of major contributors to the discipline of computing such as Alan Turing.