Hold Circle + Up or Down to put backspin on the ball.
Change shot height
Hold Square while lining up a shot. This also can be used to make illegal shots. For example, hit the ball very far past the middle to chip it or break very fast to hit a ball off the table.
Fine shot adjustment
Hold L2 while adjusting the shot direction to move the pointer more precisely.
Look around table
Hold R1 while adjusting the shot direction.
Overhead view
Hold Triangle while lining up a shot.
Side spin
Hold Circle + Left or Right to put side spin on the ball.