Updated: Jul 19
Hitting the ball as close to the "sweet spot' (centre of gravity) of the club is the most important thing you can do to get maximum ball speed for the clubhead speed you create. The reason it feels so good when you do, is that this is the point where there is no vibrations or twisting.
We all get why that is good for distance, what is less understood is how involved it is with direction. Particularly your woods. Look at "Gear Effect" to learn more about how off centre strikes create curvature in flight.
In order to be able to problem solve in any game area, you need to know where you just hit it on the face, or you can fix the wrong problem.
Feedback is key. Trackman measures this, but if you don't have one available, buy the foot spray in the image below. After a while, your feel will be educated enough to be trusted. With driver especially, 1cm off centre can make a square face delivery fade or draw. So training your feel to pick up on small distinctions like this can stop you from incorrectly framing the problem and potentially interfering with something that wasn't an issue.