I have a "trainer education" room at my club set up for training our trainers. We have class every week with homework, discussion, demonstration, etc.
There is a sign on the door with our creed, a quote I got from one of Brian Grasso's books, that to me defines for me what makes a great trainer:
JP Fitness Trainer University
Our professional commitment and creed:
“I intend never to stop learning, considering, and evolving as a professional… Even if that means the declaring my views wrong at times. Professionals who hold strongly to one point or philosophy without considering the merits of other training styles are doomed to a marginal career, reaping marginal success.”