My personal preference is to get on my toes. Try it again, but this time as you lower the bar try to push your heals to the ground. You won't be able to actually get them there, mind you, but pushing through your heals should give you the same lower body thrust you get with your heals down, and it also helps to keep you from lifting your butt.
I push my heals down as I lower the bar, then try to push my heals through the ground as hard as possible as I press. No butt lift and lots of lower body thrust, along with a really good arch.
Current PRs at 242- 495, 345, 585, 1425