Press the following buttons when you go off a jump to execute the corresponding trick.

McMetz: Press X + Up.
Superman Seatgrab: Press X + Down.
Indian Air: Press X + Left.
Nine Oclock Nac: Press X + Right.
Cordova : Press Y + Up.
Hart Attack: Press Y + Down.
Can Can: Press Y + Left.
Pendulum : Press Y + Right.
Kiss Of Death: Press X + Y + Up.
Varial : Press X + Y + Down.
Disco Can: Press X + Y + Left.
Nine Oclock Indian Air: Press X + Y + Right.
Rodeo: Press X + R + Up.
Superman: Press X + R + Down.
Stalefish: Press X + R + Left.
Ninja Nac: Press X + R + Right.
Stripper: Press Y + R + Up.
Kod Indian Air: Press Y + R + Down.
Switch Blade: Press Y + R + Left.
Supercan: Press Y + R + Right.
Tsunami: Press X + Y + R + Up.
Rock Solid: Press X + Y + R + Down.
No Hander Disco Can: press X + Y + R + Left.
Seatgrab Indian Air: Press X + Y + R + Right.
Backflip: Press R + Up, Down.