Do you ski?
When you're going through the berm, you should optimumly have your weight on your outside peddle, which should be in the down position. Once you reach the apex of the turn start to move that weight over to the other foot so that when you reach the apex of the next burm you should have your weight on the outside foot for that turn.
Imagine a ball that represents your weight. This ball travels from one foot to the other by going up your leg through your pelvis and down the other side. This ball should never stop moving but it should be at your foot when you reach the apex of the burm. When you are between turns the ball should be dead center (you're center of balance).
This is what they teach you for skiing and I found that it transfers really good to the bike for quick turns. The transition of weight may have to be quick but it needs to be smooth.
EDIT
If you need to brake do it before you enter a turn and stay off the brakes through the turn.
"May a commune of gay, Marxist Muslim illegal immigrants use your tax dollars to open a drive-thru abortion clinic in your church."