As a better player, your swing woes are often harder to diagnose because your problems are much more subtle.  Here is way to make sure that your swing is on the right track is to check the quality of your ball striking.  To do this, you need two tees, a 6-iron and some time on the range.

Set up to the ball with your 6-iron and use the two tees to bracket the club face, leaving about quarter inch of extra space on the toe and heel.  Place the ball between the tees and swing.  The object here is to make contact with the ball without hitting the tees, thereby ensuring that your club face is coming through the ball squarely.  This drill can take a bit of time to get used to, so start with short swings, eventually working your way up to full swings.  If you can successfully hit several shots between the tees, you’ll know your swing is in pretty good shape. This is how to become a better ball striker.