Knowing your shot tendencies under pressure is critical, because sometimes it is easier to play to your tendency than fix your swing at a critical juncture
Practice getting a great swing plane by placing your golf bag on the ground behind you and matching the angle of the bag with your backswing and follow through
Maintain a constant posture throughout the entire swing so that your body does not move towards the ball during the swing and cause the heel of the club to make contact with the ball