Assuming that you are not already a near-pro player, here are some tips that will help.
Maintain and reinforce the mental attitude that you are able and capable of becoming better. It is the positive attitude necessary to improvement.
When in a competitive match and you are behind in the count, patiently stick with your plan. Opportunities will arise which you can take advantage. Wait for these openings. If you are ahead, continue the mindset that got you there. Do not relax at any time. If you assume you have the match in the bag, you offer your opponent an opening.
While waiting to play, watch other players. There is always something to be learned from those who are higher and lower skilled. Watch how they shoot. Follow they analysis process, how they get down on the ball, pre-shot routine, and stroke. See how that correlates with the success of each shot. If unsuccessful, figure out why. When a shot was well played, observe and identify the pluses.
You need discipline and constantly work on improving your level of self-control. And to move that improvement forward requires that you practice as much as can be done within your schedule.
Your practice has to be focused. Improve your skills based on setting up and shooting shots that need improvement. Discoveries of weaknesses during a match will provide the material for the next practice session. Don’t go crazy with practice, but you do need to put in enough effort to achieve noticeable results.
Keep working on attainable improvements. Your whole pool playing lifetime will be spent finding little areas to improve. The complexity of the Green Game is fascinating. Playing pool is a wonderful way to pass your lifetime.