My advice to you would be to focus on trying to push your feet through the ground through your heels as if you're trying to crush the floor underneath you. If you focus on this part rather than just "opening the hips," you'll naturally open your hips up with the violence necessary to elevate the bar upward. For me, I know it helped to stop hearing "open your hips." It helped to just understand that I needed to push really hard against that ground to get the height I needed (among other technical things). When I was told to "open the hips," I completely missed the violence of action needed and just extended my hips, which is missing the entire point. You don't want to jump off the ground. However, if it helps you understand the explosive violence that needs to occur in that second pull portion, then I think I'd rather you "jump," which is something that can be corrected later, over not fully realizing your explosive potential. Besides, with heavier weight, you won't really be jumping anywhere!
I hope this helps you in some way.
Javier A. Sanjuan
Olympus Barbell Club
Dear God, please help me lift heavy and be awesome. Thanks. Amen.