you don't need your body to be that counter rotated going into the jump for a back 3 either. try and keep your body a little more stacked over your board and your shoulders closed.
ideally you want to approach from the left side, have a nice smooth heel carve going to your right, then as you approach the bottom of the jump get on your toes and hold a nice tight edge going up the lip.
heres a little picture i made that shows you what your "set up" turns should look like
you want to time it so that you are right in the middle of your toe turn as your front foot is just about to leave the lip or else you'll turn too much and drift back to the left side instead of keeping your momentum going straight off the jump.
once your front foot is at the top of the lip but still on the jump you want to pop with both legs evenly and throw the spin in one nice fluid motion. it helps to think about putting your chin to your shoulder and keep your eyes looking behind you as to keep your spin going smooth and not to jerky looking.
dont stop spotting your landing when you can see down hill cause you may not come around all the way, try to spot something thats a little more towards the left of the landing to keep your spin going a little more before opening up for the landing.
hope this helps and let me know if i need to clear anything up.