what i do is find ramps or bumps and i ride at it, in the middle of the ramp start holding down and left or right and left then mabey quarter of the way to the top slam the hand brake(R1) if done correctly should be spinning By the way this is for spins.
And if you do it on bumps just ride at the bump fast then all at once slam down and left or down and right + the R1 Button
Good Luck!!!!!!!!!!!!!!