There was a great discussion of foot launch technique found here: http://ozreport.com/forum/viewtopic.php?t=14994. You'll love the photos, especially of Kari Castle.

Dustin mentioned to me, that on launch he squatted down and grabbed the downtubes down low to bring the glider up high and off his shoulders with the hang strap tight (on harnesses with sliders it is only tight if the slider is at the bottom of the rod). The down tubes rested on his upper arms and they provided the pivot point.