Two things must occur at impact—when your club face contacts your ball during your downswing—if you want to learn precisely how to drive a ball straight every time.
First, you must appreciate the face of your club must contact your ball squarely at impact in learning how to drive a ball straight every time.
Second, you must realize the face of your club must contact your ball on a path that matches your target line–the imaginary line that runs from your target back to and through your ball– in order to hit straight golf shots.
The above two factors determine the direction of your ball.
A combination of direction, trajectory and distance determines in which direction, how high and how far your ball will fly.
Trajectory is significant because the higher the trajectory (height) of your ball flight the more vulnerable your golf shot will be impacted by wind conditions, especially by cross winds.
The distance your ball travels is determined by the swing speed of your clubface, another important piece of information when learning to hit straight golf shots..
It is most difficult, if not impossible, to hit a perfectly straight golf shot when applying conventional golf swing instructions because of the necessity of manipulating your club face in some manner during your golf swing in an attempt to square your club face to the ball at impact on a path that matches your target line.
The reason for such difficulty is you never know to what alignment and path your clubface has rotated at the completion of your setup proceedings.
Thus, you do not know whether to swing the clubface to the outside, to the inside or directly along your target line during the takeaway of your club face in an attempt to manipulate your clubface to a square alignment on a path that parallels your target line when your club face contacts your ball at impact.
One way to consistentlyhit the golf ball straight is to move one or more body parts in an exact manner a prescribed number of times either between the time you grip your club with your left hand and then your right hand or immediately after griping your club with either an overlapping, interlocking or baseball style of grip.
This is necessary to rotate and lock-in your club face to a square alignment and an on line swing path.
Then it is just a matter of assuming a a comfortable stance and posture to your ball, centering the sweet spot of your clubface as near as possible to the back of your ball and aligning your shoulders parallel with your target line to complete your set up proceedings.
From this point it is just a matter of keeping a steady head (a must in order for the club face to bottom-out at the point it strikes the ball) and executing a simple golf swing.
Another way to drive a golf ball on a straight path directly to your target is to assume one of the types of grip addressed in the book, How to Lock-In A Perfect Grip, a golf grip that squares the clubface on an online swing path the instant such a grip is formed on the club. Then merely follow the steps outlined above.
Neither the overlapping, interlocking nor the baseball styles of grip square the clubface on an on line swing path, the very reason why it is necessary to move certain body parts in an exact manner a prescribed number of times either during or immediately following such a conventional grip in order to rotate and lock-in the clubface to a square alignment and an on line swing path, as discussed above.
There are more than 100 techniques to lock-in a square clubface and an on line swing path during the setup proceedings, many of which are discussed at http://lockedingolf.com and in such books as How To Hit A Golf Ball As Straight-As-An-Arrow, also addressed at the Locked In Golf website.
You then will know how to drive a golf ball straight every time.