Instructors sometimes differ on the value of a one-piece takeaway, but golfers from Ben Hogan to Annika Sorenstam all stress the importance of "maintaining the triangle" or "maintaining the V" during their golf swings. Doing so gives you a wider arc and keeps you from twisting the club with your forearms. Maintaining the V doesn't mean you stiffen your arms; rather, your arms stay straight longer because you turn your shoulders sooner. The "V" is the letter formed by the proper placement of your arms when they are extended straight at address.
Take your normal address position with your club. Bend forward from your hips and let your knees flex slightly. Your arms should hang almost straight down, with no more tension than necessary and with your triceps resting lightly against your chest. This is a very athletic posture, as if you were going to squat down and pick up something.
Start your takeaway by turning your shoulders. It will feel as if the butt of the club is pointing toward your belly button as you turn. Don't twist your forearms or lift the club. Because your triceps rest lightly against your chest and your spine is tilting toward the ball, your hands and club will automatically begin to move upward as you turn. When your hands are about waist high, the shaft of your club will be parallel to the ground and pointing away from your target. Annika Sorenstam, in a Golf Channel interview, said one of her swing thoughts is to keep her right elbow straight during her takeaway.
Bend your right elbow at a 90-degree angle to lift the club to the top of your backswing and cock your wrists. Your right elbow will move slightly away from your side as you finish your backswing. If you are extremely flexible, you may feel as if your right elbow stays fairly straight until your hands are around shoulder height. You should feel as if both elbows point toward the ground; if they don't, you've twisted your forearms and altered your swing plane. This will cost you both accuracy and power on your downswing because you'll waste energy putting the club back on plane.
Start your downswing by shifting your weight back to your left side and let your right elbow move a bit closer to your side. This isn't a big hip slide; rather, it feels as if you just set your weight back on both feet equally to return your hips to your address position. (Your hips will actually move past your address position, but this is how it will feel.)
Keep your right elbow close to your side and, as the club reaches waist high on the downswing, straighten your elbow to recreate the triangle. This will cause your wrists to uncock and create the most possible clubhead speed. Ben Hogan wrote that if a golfer has "performed the swing correctly up to (this) point, he is so set up that he instinctively hits through the ball and follows through correctly. You can't keep from doing it right."
Let the club's momentum pull you through to your finish. Your elbows will stay straight until they are around waist high after the ball is gone, then your left arm will have to bend to slow the club down for your finish.