Make the Casper as one of your character's special tricks for flatland (set its command to Left, Right, Triangle). Get the special filled and do the trick. Now, while in Casper stance, press Left, Right, Triangle to switch to Anti-Casper. Also try pressing Left, Left, Triangle to put yourself into Primo stance, then pressing Right, Right, Triangle to put yourself into the Truckstand stance. Keep pressing Right, Right, Triangle quickly and repeatedly while in the Truckstand stance to keep doing multiple Truckspins to rack up points. You can switch to any of the above mentioned stances to another just by pressing in the command, but you can only do Truckspins while in the Truckstand stance. Enable the "Perfect balance" cheat to do this easier.