Tony has it spot on, it is a concert between driving / sheeting and cunningham.

In a puff, ease main (talking inch or two MAX), point up a bit ( a degree or two). We generally ease main slightly delayed from pointing (i.e if point is going to take more then a degree or two, ease). If the main is constantly eased (i.e two inches of main sheet out more then it should be), cunningham goes on a bit to de power main.

On the F18 (at least C2 / Capricorns) the crew does main and cunningham as they can sheet in and out faster, this also requires a lot of practice and good communication with skipper. The skip takes the main in lighter air (and of course downwind).

Side note: if the cunningham is max on and you are still overpowered, take a look at diamond tension, probably could be tighter.