One reason that you hit good shots on the range but then struggle on the course is because, on the range, you align yourself with your surroundings.
You stand parallel to the edge of the range mat, parallel to the bay wall or divider and then you swing parallel to your surroundings. Once out on the course, these surroundings disappear leaving you with no reference points and course designers are very good at aligning tee boxes towards trouble to catch out anyone who swings parallel with their surroundings. However, what you are also doing at the range without realising it, is swinging parallel to your body’s alignment and this is out on the course with you.
Look at how you set up ready to hit your golf shot. You stand parallel to the target line. Learn to swing you golf club with your body alignment. As you take the club away on the backswing, at waist height the shaft of your club should be parallel to your toe line. You can check this by placing an alignment pole or another golf club across your toes but slightly to the right. As you swing your golf club back, look at how it becomes parallel and just forward of the pole or club on the floor.
Once you have achieved this position, continue to the top of your backswing and again the position that the club should be in is parallel to your target line and parallel to your toe line. Now swing your golf club back down and after you have struck the ball and moved through impact, again the club will become parallel to your toe line. If you place an alignment pole or club on to the floor in line with your toes but this time to the left of you, you will see the club becoming parallel but forward of your alignment line once more as you follow though.
Make some waist height swings where the club swings to a position in line with your body alignment on both your right and left side. Hit some balls like this and see how straight you hit the ball. Once you are used to this, swing all the way to the top of your backswing and again work on achieving a club shaft position parallel to your toe line, then strike through the ball.
Working on swinging the club in line with your body’s alignment when you are out on the golf course will help you achieve much more accurate shots.