Tips on doing backflips???????????

on my trampoline i am able to do whats called a gator flip where u dont bounce u just flip and i could land dat,, i could also do a regular backflip with no problem plus a backflip 180,, i wanna try doing a backflip with my friend tomorrow but idk how hards its gunna be so if anyone could tell me if you think i would be able to do one dat would be coo,, but also tell me some things i could set up to avoid neck injury