You must close your stance so that your feet are not spread farther apart than the width of your hips. This facilitates a pendulum type of stroke. It also allows your body to perform the stroke rather than your hands.
Your wrists must stay locked. If you break your wrists, you disrupt the tempo of the swing and the ball will not go the intended distance. Press your palms lightly together to eliminate any hinge of the wrists.
Commit to memory how far your ball carries based on how far back you bring the club. With a pendulum stroke you take the club back the same distance you swing it forward. Think of your club as a clock's hour hand. Bring the club to 7 o'clock and measure how far the ball goes. Try the same at 8 and 9 o'clock.
Familiarize yourself with how your club hits the ball varying distances depending on where your ball lies. When you are on the fringe of the green, you won't need as wide a stroke as you would from the fairway. Grass on the green's fringe is shorter than the fairway grass. Longer grass will slow down your stroke.
Try to put 80 to 90 percent of your weight on your left foot and don't shift that weight during the swing. This helps assure that your club head will strike the ground directly under the ball.