I have indeed. I was working with a High School Auxilliary (Flag Corps). In the beginning it was a little difficult to get all of them to put forth the desired effort but, just like any 16 year olds, they had to test my limits. I suggest pushing them to improve every time they train. Knowing that the form and techniques they learn today are more than likely going to be what they remember to use for many years to come keeps you on your “A” game. To motivate them, I used partner and team drills. I found that they work harder in groups and motivate each other. Run some relays and watch them cheer each other on. Also, give everyone a personal “Good Job” at some point. It can be secretive while having a water break, or blatently announced before the masses but nobody gets left out. When they get singled out (for any reason) their response is always enhanced. Tell a girl she’s doing a good job and she wants to do better, tell her she’s not giving you her best and she works harder, knowing that you are paying attention (or sometimes cry if you aren’t sensitive about it; oh the tears and emotions of 16 year old girls. They might even cry over the “Good Job” too, so be prepared for that…I wasn’t) For the most part, when you get them to cooperate they motivate each other.