My 2 cents: just don't push your butt out, rather try to rotate with your upper body to the direction you are turning. What also helps: turn your head towards where you wanna go.
If you still want to touch the snow, then don't focus on touching it with only your left palm (in case you are regular), because then you'll end up reaching for the snow and pushing your butt out.
Instead try to touch the snow with both palms - that will help you with the proper rotation. Don't try to touch the snow behind your butt, reach a bit more forward to the tip. It'll help.
Cheers,
István