You as the Coach
Part I
 
When coaching a friend, club member, or teammate in tournaments there are a few things to remember.  First, try to be positive and encouraging to him.  Even if your player has played poorly, try to find something encouraging to say while still giving solid advice.  Next, try to keep your advice to 0-2 things.  If he wins easily, you probably shouldn’t say much of anything.  If he plays poorly, then you can give 1-2 short pieces of advice.  The advice should be in relation to the opponent.  Most players understand that they are missing backhands or can’t serve short.  But the best advice should be as it relates to the other player – his strengths, his weaknesses, his patters, etc…  Also, be willing to listen.  Sometimes students have questions or problems that need solved – so be a listening ear. 
 
 
You as the Student
Part II
 
I recommend only receiving advice from players who know your game and have coached you in the past.  If the player doesn’t know the details of your game, then you are probably in for an arguing match, which doesn’t put you in a winning frame of mind.  If you have a coach who has helped you in the past and is knowledgeable about your strategy, it can be a wonderful winning combination.  Before the match, you should briefly talk with your coach about the strategies related to that opponent.  You should give your coach a note card with several key points that you want to remember and ask your coach give his own advice as well as remind you about some of the points on your card.  Between games, there should be a short 5-10 seconds of reflection from you.  Next, the coach should talk for 15-30 seconds.  Then there should be about 15-20 seconds of quiet and rest.  After the match, you should have a few minutes to recover, a brief time of discussion about the match, then a brief time of focus for the next match.
 
 
You as the Forced Student
Part III
 
Unfortunately, there are times when you are forced to receive coaching from someone who doesn’t know your game.  If you are on the Olympic team, then you will obviously receive coaching from the Olympic coach, even if he isn’t your primary coach.  If you are playing at the NA Teams, then you will probably receiving coaching from your teammates, even if they aren’t the ideal coaches.  There will be times in your playing career that you will be coached by someone who you don’t agree with or someone who doesn’t know your game.  What should you do?
#1 Prior to the tournament, do everything possible to change coaches.  If that isn’t possible, then follow the rest of the steps.
#2 A few days before the tournament, e-mail your soon-to-be-coach some videos of yourself playing.  Explain your strengths, weaknesses, patters, tendencies, and how your game has been progressing.  Let the coach know your goals as well as your training routines and warm-up routines.
#3 On the tournament day, have a brief moment with the coach explaining how you are feeling and discussing some strategies for known opponents.
#4 As you begin your first match, give your coach a note card with some self reminders about your specific strategies for that opponent.
#5 Between games, don’t argue with your coach.  Listen patiently and don’t force your opinion on your coach.  You can try to clarify his advice, but don’t argue with him.  If he gives you very very very bad advice, I would recommend not obeying.  Ultimately it is your responsibility to win the match, not your coach’s responsibility. 
#6 After the match, thank the coach for his effort and communicate with him some of the positives and negatives about the match.