Improvement
"It's not the hours you put in, but rather what you put into the hours."
Idea's for improvement:
Track your play - keep a notebook with you at the pool hall, after a match (league, tournament or just matching up) write down how you did, strengths, weaknesses and any specific shots you had difficulty on. I'm willing to bet if you do this, you will start to see patterns of all the items.
Practice strengths and weaknesses - put in time on problem shots you noted from above. If we can eliminate one problem shot that we have each week, then naturally we will have fewer and fewer problem shots. Practice your weak areas of your game, but also spend some practice time on your strengths.
Be honest with yourself. No Excuses anymore. These 2 statements will make a change in any ones game. Be honest with yourself when it comes to all aspects of the game. Some players think too highly or lowly of themselves. Don't have expectations but rather continue learning and improving. No excuses is a powerful addition to your game because no longer can you blame rolls, table, luck... but rather own up to how you played and the decisions you made.