Those of us who do a little bit of coaching, or just mentoring (which is more what I'm doing), what are the little things that a lot of people do that annoy you?
The first is when people rock up early, and then muck around for 10/15 minutes. Obviously you'd expect younger kids to do it, but if you're part of a senior cricket club, you should have the nous to get someone else who is there early to have some throwdowns with you, or do some proper catching practice. Not practice your left arm chinamen, or batting with the wrong hand against a tennis ball.
The other one is guys going down on one knee to field the ball, especially in fielding practice when it doesn't matter if you make a mistake. Attack the ball and get better, don't spend the time getting into worse habits for safety's purpose.