If you want to win more matches, start by "losing less".
Six common ways I see players LOSE matches
1. Missing net for no reason
2. Missing wide for no reason
3. Changing directions for no reason
4. Double faulting
5. Missing returns
6. Missing serve and return +1s
If you can reduce these errors and make them less than your opponent, you'll find yourself in control and ready to win A LOT more matches.