If adults. Something similar to:
Boys I will play advantage as much as I can. You know your players better than I do. Get to them before I do. I will work with you as much as I can. I can't avoid Red cards.
Away team you call in the air.
That sounds like what I'll be saying to the juniors! I'm known for my high card count (About 50 YC and 8 RC)I have a new, simplified version for this season:
"Yes I am THAT b*stard from last season, away team captain you get to call, heads of tails?"