1. Take a grip 1 finger wider so you can get your knees pushed out to the side a bit in the setup.
2. You never actually get a finished setup. You are wiggling and then start to pull. Get your setup dialed in with hips a bit lower (knees flush with the front of your arms) then pause, then move to squeezing your back.
3. Spend a solid couple of seconds squeezing your back flat after the setup without letting your hips drop. Think chest up with hips frozen in place.
4. Don't let go of the bar in the middle of a set.