Do you have a game plan when you play? Or do you just wing it and hope?
Many players mostly wing it, to their detriment. Most have patterns they use, but often they haven't really thought them through. Every serve and receive should have purpose; otherwise, you are playing without purpose. Often the plans they do have don't take into consideration the opponent's strengths and weaknesses. For example, if you are a looper, you probably have patterns to set up your loop, but how much do you focus on adjusting these techniques and your loop itself (placement, speed, spin, etc.) to your opponent?
What is the strongest part of your game? What is your opponent's weakest? How can you connect these two? Failing that, how can you get your strength against your opponent's average, or perhaps your average against your opponent's weakness? You need to be looking for ways to force these match-ups. (See "A Levels Approach to Tactics.")
If you have a good serve and loop, it's not enough to serve and loop; you have to know where to serve and loop. For example, I'm forever reminding players with good loops that they normally shouldn't just loop to the backhand, and then look for a chance to attack the middle or wide forehand, where most players are weaker defensively. Why not plan to attack the middle first? (At the higher levels, against a very good counterlooper who is waiting, you might not want to do this - but often they are hanging around their backhand side, leaving the wide forehand somewhat open. And yet, even at that level, the middle is usually the weakest spot.)
Think about someone you regularly play against. What is he uncomfortable against? You might want to consider how others play against him, since it's possible you are missing his problem areas. Then figure out how you can best match up against him.
But don't think of it as just one tactical solution to one player. The key is to make it a habit to develop game plans - something you automatically think about and implement every time you play. When game plans becomes a habit you'll get your better shots into play while picking apart the weaknesses of your opponents, leading to more upsets, beating your peers, and dominating against weaker players who might have given you problems before.