Cameron and Shane drive it home every time we go to pick up something heavy, "Set up for your lift tighten your abs, squeeze your butt, lock out your knees, and screw your feet into the ground.” This is how we should set up for every lift. This is allowing your body to lift with the utmost efficiency and puts your body in the correct form to prevent injury.
I personally had a scare last week. My hamstrings are very tight(something I am working on). My tight hamstrings prevent me from being to get into a really quality low range of my dead lift. I have to compensate to reach the bar which doesn't let me start with good spinal position. Because I am beginning my lift a little off when I was in the middle of my deadlift pull I allowed my abs to relax just a bit, but is was enough to overload the small muscles in my lower back and was unable to continue to hold the load I was lifting. It resulted in a very stiff back for the next few days.
Fortunately with some rest and stretching I am feeling so much better just a week later. But now I know where i need to do a lot of work to be able to get into position. So remember, before and throughout the entire lift, tight stomach, squeeze your butt, lock out your knees, and screw your feet into the ground and mobilize when you are not at the gym. Here are a couple videos to help with that.
CrossFit - "The Deadlift Set-Up" with Kelly Starrett
Dead Lift Prep | Feat. Kelly Starrett | Ep. 105 | MobilityWOD