i always love to flank the enemy through bushes

Any tricks for making this happen? For example, back in the day when I played with CO2 I would unscrew my tank momentarily which made the infamous loud hiss. Then take a shot with the remaining air in the gun and you get the traditional "ppmmpmpmpmpmpmmm" of an empty tank.

Screw the tank back in and sit tight. They think you're out so they'll likely try to charge before you can refill. Time to pick'em off