I usually let the situation dictate whether or not to be aggressive or passive. If I'm set up on a bird I roosted the night before, I start off passive; if he responds immediatly, then I keep it passive. He knows I'm there, which means I've got his attention; so i don't want to overcall him, and have him wait for me to come to him. If it is an area with alot of hens, then I call aggressively with a diaphram and a slate at the same time, to try and convince him he got a better deal in my direction. In this case, I just keep hammerin' him until he gets close, then lighten up to close the deal.