MinggPretty much this.
OP get yourself some ski blades and take it to the jumps on fiddler's next year. Those are usually small enough that you wont die on but big enough to have enough time! I tried them in Fid's last year, never actually landed one but got the crossing and uncrossing thing down.
I did some on a 15ft jump. Then went to screaming 180s and after about landing it twice, well, Im not gonna be doing it again any time soon. Landing switch while screaming aint too fun. Find a big enough jump and you should be fine