This is a fault that good players often suffer with and the evidence can be found in your initial ball flight. Is it starting consistently right of where you want it to? As you attack the ball, the club is ‘trapped inside’ when the butt end of the shaft is pointing right of the target halfway through the downswing. Get a friend to video your swing to see if you are in the same position as the image shown here. From here, if your hands release fast enough you’ll square the clubface and hit a draw or hook but if they don’t, you’ll hit a push. Either way, you will struggle for consistency throughout your long game. One shot you will never hit is a fade that starts left and drifts back to the target.
The most common cause of getting trapped on the inside is when your hips move too far towards the target on the way down and do not rotate. Work on starting the downswing by bumping your hips towards the target and then turning them. By rotating your hips, the club will stay out in front of you on the way down and your angle of attack will improve (for some handy drills on how to do this, take a look at Gary Alliss’ advice on how to stop blocking drives). The butt end of the shaft will be pointing towards the target half way through the downswing, giving you much more room to square the club and hit more accurate shots. With the club approaching the ball on a far more neutral path you should notice your shots start much closer to your target line. So work on your hip movement through impact and you should avoid getting trapped on the inside.