really difficult to do Smith/Feeble grinds
When trying to do a smith or feeble grind the game will automate the trick into a crook, blunt, or nose/tail slide. I think it would be better if you were able to do something like pressing R1/RB to...
Ideas
RB is usually used for doing darkside tricks (not added to the game yet). Hitting the correct grind can be difficult if you don't control your speed, angle of approach and make sure your using the correct stick movement. Best thing to do is just find a spot and practice till its perfect.