I will use a quote I posted in a thread before, and I think it fits this topic perfectly...
Bruce Lee: On adapting to each student
"I believe in having a few pupils at one time as it requires a constant alert observation of each individual in order to establish a direct relationship. A good teacher can never be fixed in a routine... each moment requires a sensitive mind that is constantly changing and constantly adapting.
A teacher must never impose this student to fit his favourite pattern; a good teacher functions as a pointer, exposing his student's vulnerability (and) causing him to explore both internally and finally integrating himself with his being."