Keep a Player's Attention and Thinking
Want to bore a six-year-old? Feed him multiball and have him hit forehands for a long time. Want to inspire a six-year-old? Put a giant frog toy on the table and tell him to hit it.
Want to bore a sixty-year-old? Have him do nonstop repetitive drills without explaining anything. Want to inspire a sixty-year-old? Have him to a range of drills that cover what he does (or hopes to do) in an actual match, from repetitive drills to perfect strokes to random drills to mimic game play, and explain the purpose of each drill and technique.
Keeping a player's interest is one of those things coaches have to learn to do. If you just spew out instructions in a bland way and just do repetitive stuff, you'll lose them. You don't treat everyone like a six-year-old or a sixty-year-old, of course - it has to be both age-appropriate and personality-appropriate. Some are more analytical than others, and some just want to hit the ball. Younger players often just want to hit the ball, while older players tend to be more analytical. Yet even younger players have their analytical side, and like to think about certain aspects of the game as long as you don't overdo it. Show them something they want to learn to do, and they'll want to know how it's done.
The more the player thinks, the more interesting it is to him as he learns. Older players often enjoy learning the thinking side as much as the actual playing side - tactics, why specific techniques are better than others, mental training, etc.
Table tennis is a game of contradictions. One of them is that you need to think a lot if you want to improve. At the same time you have to clear your mind when you are in an actual rally and let your trained reactions take over - i.e. don't think.
ITTF Level 3 Coaching Course