1 on 1
Large class or small "1 on 1" with a student is essential IMO. Getting to know what the student perceives he/she is learning and often how they learn (we all learn differently) is difficult and likely impossible unless your taking time for individual attention. Allow them the ability to be better than you, what parent would want their offsprings to have less than themselves.
This also allows you to adapt the "form" to the student`s body structure and personality, both of you become "students" at this point as your no longer just passing on information but developing it as well. Each instructor is an individual and in clubs with more than one instructor conflict is sometimes the case if individuality is not respected, no one sees the art they practice/teach exactly the same as another.
A dojo that has more than one instructor that has been coordinating classes for a long period of time is IMO a club with ability to adapt, one on one training has developed the individuals to allow freedom of expression and diversity (this is a good thing) will exist and students have various flavors to try but its still ice cream right?
I follow and remember my teacher(s) path not their footsteps, and I look for paths they may have missed as I travel where they have been. I ask those I teach to do the same.