Warm-up is not practice - Some players confuse warm-up and practice. Each player should make a special effort to hit shots directly to the opponent. A player should provide the opponent a 10-minute warm-up (5-minutes if there are ball persons).
Warm-up serves and returns are taken before first serve of match - It's common to wait until it's your turn to serve before taking a few warm-up serves. However, a player should take all warm-up serves before the first serve of a match. A player who returns serves should return them at a moderate pace in a manner that does not disrupt the server.
