Every golfer has moments when they wish they could hit a draw. A draw allows you to safely play a shot that might otherwise go careening into the woods. Many golfers think this skill is reserved for the elite. But I'm here to tell you that with practice, anyone can do it. (Learn how to improve your golf warm-up.)
Note: The following instructions apply to a right-handed golfer hitting a shot that curves to the left.
Most golfers understand that the clubface has to be closed to the path to put spin on the ball that makes it curve to the left. The term "spin" in this context is actually a bit misleading. What a player does is tilt the spin axis of the ball at impact. There is no sidespin; it is actually backspin, but on a tilted angle. (Watch Scott Stallings' workout.)
Curving the ball to the left could be as simple as making sure the clubface is closed to the path of the club head. However, it needs to be more precise than that, because there is a specific target in golf.
Science has proven that the trajectory of the ball is 80% dependent on the angle of the clubface at impact (spin accounts for the remaining 20%). This is a change from the old 9-ball flight pattern, which assumed the path was determined solely by the initial direction of the ball. Thus, when hitting a draw you need to aim your clubface slightly to the right of the target.
Once you have done this, you need to tilt the ball spin axis needs to the left. This means that the path has to be further to the right, so that the clubface is actually closed to the path.
Hitting a draw as described above is easy to execute if the club has zero angle of attack. Realistically, most shots are hit either with a negative attack angle (with irons, hitting down on the ball) or a positive angle of attack (with the driver, swinging up through the ball. (See Stability Training to Improve Your Swing.)
To understand this concept, picture a hula-hoop in the path where you swing the club. At the bottom of the hula-hoop is a zero angle of attack. The club is going neither up nor down the hula-hoop, but instead is traveling directly at the target. If the club strikes down on the ball, it occurs before it reaches the bottom and is pointed to the right of the target. If you held a pencil parallel to the hula-hoop two inches from the bottom before impact, you would see that the tip of the pencil is pointing right. The opposite is true when the club has swung past the bottom and starts to swing up. The club tracks up the hula-hoop and to the left, so the club path is now actually to the left.
To draw a shot, your swing direction has to be to the right if the attack angle is going to be positive and slightly to the left if negative. You can do this by aiming right or left (depending on the angle of attack) of the shot you would take if there was zero angle of attack.
Once you have the right mental picture of how a club works through the ball, you should be able to curve the ball in any direction and have complete control of it.
Good luck and keep swinging.