When in elevator, extensions, and/or hands, some fliers hips get shifted. Here are some tips to fix this:

1.) Practice on the ground - Practice hitting your stunt on the ground first. Think about staying tight and squeezing.

2.) Check Stance - Now pay attention to the way you stand in general. People commonly stand shifted to one leg or the other for a comfortable stance. The same thing is occuring in the stunt, and is why it is not noticeable in the air.

3.) Shift back - Try to shift your weight back to the other foot. This might help you adjust to the proper position.

4) Hip over- Also try to move your hip over to the other side. This should realign your body and get your hips straight.