Getting and maintaining tension is crucial for a big deadlift. This is accomplished with upper back and lat tension. To make sure you have it, use the barbell as a counterbalance to get the chest up and weight back (armpits above the bar), and then "make the barbell click."
Get the slack out of the bar before you begin the lift. Put another way, bend the bar before you pull it.
As a member of an elite Navy Special Warfare Combatant-Craft Crewman team that often finds itself in the Third World, Craig Weller has learned to improvise when it comes to his workouts.