I posted this on a different thread but it works for this one too:
"Only real problem I see is the jerk right before you pull the weight. You dip down a little and try to get some stretch reflex out of an exercise that doesnt allow you to have one. When you do that little jerk at the bottom, deadlifting becomes 2 pulls. The first is the slight bend being pulled from the bar. The second pull is your actual deadlift. That little bit of wiggle in the bar before you start pulling needs to be pulled out before you actually begin your ascent.
Next time you go to pull, when you get set, literally pull yourself down to the bar and get that slack out. You'll know you are doing it right because you will feel the bar bend a little and you'll tension in your hamstrings before you even start the actual movement. Also, when you do start, the pull will be much more fluid and you'll be able to take advantage of all your leverages. That tension in your hamstrings will act almost like pulling back on a slingshot. The weight will fly off the floor.
I had the same problem for years. All thourgh 8 years of football and my first 2 years of competing. I changed it this past year and started working the slack out before my pulls and its taken my deadlift from 740 to 804.
Let me know if this helps!"
Everything said above is why your hips come up first.
And whoever said he was fucking around with the bar too much, x2.