Tennis Balls - no one gives them a second thought

Tennis balls - no one gives them a second thought until its time to play that all important match.
What I always tell my customers is if you are playing a tournament, make sure to find out which ball will be used, and buy it.
Buy that ball, and play with it in the week or weeks before to prepare yourself. Every ball plays different, just like every racquet and every surface.
So, give yourself the best chance and make sure you practice with fresh tennis balls, not flat ones.