Most of the problems I hear about from my students can be traced back to their short-term thinking. We live in a fast paced and hectic world. We eat at fast-food restaurants, both parents are working and we feel we need to be very competitive in all phases of our lives. I believe this short-term thinking is the largest cause of what most players call "choking."
When I first started teaching, I got trapped in this kind of short-term thinking. I tried to produce hundreds of clones (excellent tennis players). In many cases, I lost track of their goals and aspirations. This approach did produce many excellent tennis players, but at what cost? Are they still playing tennis and do they still love the game?
Soon I learned to teach players how to love the game and promote the game for a lifetime of enjoyment. Once a player loves the game, you will always see positive improvement. Many players want immediate results (wins). They cannot handle the "down-time" or the times when they are in a "slump." Once a player is taught that this is highly normal, you will find they recover much quicker from their slump.
I have students whose parents push them too hard. They come to watch my lessons and they comment that their child is not concentrating, and that they are having too much fun. I tell them that is why they like coming to my lessons and that is why they want to come back. They are just kids and they should be having fun. If they enjoy the lesson, they will learn more. Each player can decide his or her level of competitiveness later.
Think in the long-term for your game. Two of my favorite students have been playing for years. One is 72 and the other one is 85. They both still love the game and both have been through many "ups and downs."
Good luck on the court!
