While defending to receive a shot from opponent, right before the opponent hits it, make a move in any direction and then in the opposite direction. You will always receive the ball at the opposite direction where you moved last.
In Career mode, play the "Defend The Prize" mini-game repeatedly. Choose one prize and stand in front of it (ignore the others). Simply defend that one prize. You will easily win the mini-game every time and be able to increase your Volley skill as quickly as desired.
Unlock the following rackets by performing the corresponding tasks:
RACKET - HOW TO UNLOCK Frying Pan racket - Get three strikes in a row in the pin crusher mini-game. Guitar racket - Defeat duke or king in a SPT. Tambourine racket - Make 100 lob shots. Wooden racket - Beat king of players mode. Blue racket - Win all four Grand Slams in World Tourmode. Blue Hand racket - Hit 1,000 Max serves in Career mode.