Many times during a match, players have a tendency to get caught up in the competition making it difficult to focus on things they can do to improve their chance for success.
One of the most underrated aspects of this plan for success in a match is the ability to think the correct way in between points. Before the point starts, remind yourself of your basic strategy (serve and volley, consistent baseline play, or moving forward as the point gets longer for example).
Just prior to serving or returning serve, pick one basic technique idea (watch the ball all the way to the point of contact, follow through, shoulder turn, move your feet, etc.) and make that your focus.
Immediately after the point ends try to assess what you did well, what you can do to make a correction for the next point, or pick one technique idea that may have helped you execute your strategy better and adjust it. The best players in the world go through this process over and over again and do not allow a lot of additional thoughts to enter their mind. There are times on the changeovers that they may get a little more detailed in their idea. However, this in between point routine inevitably separates the best players from their opponents.