3. It's possible to become too analytical in the middle of a match, which will keep you from letting your strokes take their natural flow, but you don't want to shut down your analytical abilities, either. If you miss a shot you shouldn't have, you'll dwell on it less if you take a moment to figure out what you did wrong, then say to yourself, "Okay, I won't do that again." It's usually a good idea to repeat the stroke right away with the correct motion. You might very well make the same error the next time the stroke comes up, but just go ahead and apply the same process. Eventually you will get it right, and in the meantime, a little extra optimism won't hurt.
4. Learn versatility. If you have only one playing style, and it's not working, your lack of strategic options also creates a shortage of mental safety valves. A key factor in psychological health in general is feeling empowered to choose different courses of action. If you have a Plan B, C, and D on the tennis court, the failure of Plan A is unlikely to cause despair. Tennis players often lose because at least a part of them secretly gives up. You won't give up while you have something else to try. Learn to play every part of the court and hit every kind of shot with every kind of spin. You'll likely uncover a weakness in a seemingly invicible opponent. Variety makes the game more creative and interesting, too.
5. Look alert, energetic, confident, and happy. Looking so will actually help you be so to a significant extent, and it will keep you from giving encouragement to your opponent. If your opponent is at all prone to choking, your look of ready confidence on the verge of seeming defeat might keep just enough doubt in her mind to make her cave under the pressure of closing out the match.
Books with good chapters on mental toughness:
- Vic Braden's Tennis 2000: Strokes, Strategy, and Psychology for a Lifetime
- Pat Blaskower's The Art of Doubles: Winning Tennis Strategies
- If you want a entire book on mental toughness, check out Dr. James Loehr's Mental Toughness Training.