What I did, I learend back first cause I never comited wel to the 360. I learned the back in a powder jump, maybe thats the best option cause you feel the rotation for first time with you skis ina safty place. Do all the backies you can in the pow jump then when u land them all try to get the jump biger. Always think the timing you will put to u backflip cause in big jumps u can overrotate and that hurts. Big air, do them slow, lil air do them faster.