Captains, Patches and Team Pizza party
I set up several competitions for the team. First - to motivate them as a team we took a baseline at the beginning of our winter session and recorded the overall team ranking. I challenged the team to improve by 2 badges by end of winter for a team pizza party. Next, player with the highest badge score and the next two players that improved themselves the most from the start of winter would earn Captains bands for the first month of spring season. I tried to reward both overall excellence as well as hard work and self improvement this way. Finally, each week for the player that improved the most/leveled up the most in each technique we focused on got a skill patch.
Overall its worked like a charm. While I've not gotten 100% participation at the level I was looking for, with the exception of a few the kids have really taken to it. We are going to continue with this though spring season in a slightly modified form.