Most leadership messages are best delivered as directly as possible. The smaller the intended audience, the more likely the message will be heard.
I expressed this recently to my student leaders, who were hoping to inspire more personal practice from the ensemble. A message to the entire group from me will be much less effective than a message to the tenor 2’s from their section leader. A single accountability partner can be even more effective.
The message is: make it personal, make it direct. That’s the way it’ll stick.