Here are some things you can be doing to get better at tennis:
Watch this video in which Bear Bryant explains how to beat people who are better than you (and, by contrast, what you have to do to keep from losing to people who are maybe not quite as good as you):
2. Watch this video (about intelligence) and make sure you have the same sort of growth mindset when it comes to how you approach tennis:
3. Go here on the USTA site and read (and think) about the core values of successful tennis players.
4. Go to the USTA site and learn (and think) about the match tips found there.
5. Call a friend and get out and play some tennis. One of the best ways to get better is just to get out and play for fun.
6. Call three friends and get together to play some doubles.
7. Watch a match on television. Turns out the pros know a thing or two about how to play well. Watch what they do (especially how they move their feet during points) and see if you can't learn something.
8. Watch some clips of pros playing on Youtube.
9. Find (and watch) some instructional videos online that will help your tennis game. (There are plenty listed below, as a matter of fact.)
10. Do some conditioning work. Get out and run a mile (or two). Run some sprints. Run some stairs. The faster you are (and the longer you can stay fast), the better you'll be on the court.
11. Jump rope. It'll help your footwork as well as your endurance.
12. Hit against a wall (ground strokes and/or volleys) and see how long of a rally you can manage.
13. Play the number game with a friend (i.e. see how high of a rally you and your friend can work together to achieve).
14. Practice your hand/eye coordination by bouncing a ball on your racquet. To make it more challenging, switch sides of the racquet on each bounce. To make it even more challenging, alternate every bounce between sides of the racquet and the side of the rim on every third bounce.
15. Spend some time reading through one of the following documents related to the rules of tennis:
the official rules of tennis: http://www.itftennis.com/media/136148/136148.pdf
the basic rules of tennis (in simple terms): http://www.buzzle.com/articles/basic-rules-for-playing-tennis.html
the rules of tennis, in common language, but with lots of details and etiquette and such: http://blue.utb.edu/jloff/1127/ch4/ch4.htm
16. Spend some time reading through an article on the Links page related to managing the mental/emotional part of the game of tennis. (You'll find those articles near the bottom of that page.) And while you're at it, check out item #36 below for more advice on managing the mental side of the game.
17. Take a basket/bag of balls to the court and practice your serve.
18. Practice your footwork/agility by setting up a course (at your house or wherever) that requires you to run forward, backward, side-to-side, diagonally, etc. Then run it as fast as you can. Time yourself. How fast can you run it? How many times can you run it in a row without having to stop due to exhaustion?
19. Make a list (or read over it if you've already made one) of positive/encouraging things you can say to yourself when you're not playing well or you're behind in a match.
20. Spend some time online looking for tennis tips to see what sorts of new ideas you can learn about.
21. Make a list of areas of your game that you think could use improvement. Then add details to the list with ideas about what you can do to address each area.
22. Check out these videos for ideas on conditioning and footwork:
23. Watch this video about tennis tactics:
24. Watch these strategy videos:
25. Watch this video and learn a thing or two about gripping the racquet:
26. Watch these videos and learn about some of the different serves you can learn to hit:
27. Watch these videos about how to beat a pusher (a player who returns everything, hitting slow, loopy shots, waiting for you to get frustrated and make a mistake):
28. Watch this video and learn how to "think like a pro":
29. Watch this video and learn the five things that pros do (that you don't) when hitting forehands:
30. Watch this video to learn how to move like the pros do:
31. Learn to lob:
32. Watch these videos and learn a thing or two about doubles strategy:
33. Put together a playlist on your phone/iPod/etc. that you can listen to before a match to put you in the right mood/mindset. Maybe you like songs that pump you up. Maybe you prefer songs that help you calm down. Put together a playlist that works best for you.
34. Read this article and learn a thing or two about singles strategy: http://www.teachingtennis.com/site/strategy.htm
35. Watch this video about playing with confidence and keeping your eye on the ball:
36. Watch this video and learn how to manage (and master) the mental side of tennis:
37. Improve your net game and learn to hit better volleys:
38. Get out to the courts with a friend and play a little mini-tennis: http://www.tennis4you.com/lesson-lounge/match-point/article-004.htm
39. Read this article and learn a thing or two about improving your timing: http://www.feeltennis.net/improve-timing-tennis/
40. Read this article and learn how to play tennis the "natural" way: http://www.feeltennis.net/3-things-you-need-to-play-tennis-the-natural-way/
41. Follow this link and check out the resources there that will help you improve your volleys: http://www.feeltennis.net/category/volley/
42. Watch this video and learn a thing or two about how to play without tension in your body:
43. See if you can learn to do these tricks (but please don't wear these shorts while you do):
44. Watch these videos and learn a thing or two about what it means to hustle and stay in a point:
45. Watch this video and make sure you're not calling lines like these knuckleheads: