Yelling, which might relate to the above, was also high on the list. We aren't talking about raising your voice to be heard above barking dogs. No one likes to hear constant screaming. They mentioned things such as derogatory remarks, negative comments and embarrassment. The trainer seemed stuck in one type of training.
Closed minds seem to run a potential client away fast.
Customers appreciate a trainer who tailors himself to the dog, not vice versa. If you recently left a trainer, after establishing a relationship, tell us why. Obviously, there is some overlap here. People leave for the same reasons they gave above. Most come down to respect issues.