Drum_slinger, What part are you having trouble with? Getting the sling in the right starting place? Or swinging it?
I would like to see a video of this myself. But I do not have a video camera, so I'll have to make do with a description of what I do.
Lobohunter: please let me know if this sounds like I'm doing it right? Thanks!
Note added April 27, 2006: Despite what Lobo said about the accuracy of my description of his style (next post), my description bears little resemblance to what I saw Lobo doing in his video (there is a link to it in the first post of this topic). Please ignore the description below and go watch Lobo's video.
You just drape the sling across your shoulders, so that the pocket and the ends of the cords hang in front of you. If you pulled on the pocket and the cords, you would be bending your neck as the sling pulls it down and forward.
I had a little trouble with the start of this style. I believe I mentioned I clipped myself in the jaw. Lobohunter apparently did not have this problem. But if I toss the pocket up and to the left, as I pull to the right and down on the cords, it works for me (I am right-handed, by the way). The stone in the pocket moves up and to the left, back over my left shoulder, then behind my back and down as my right hand drops (pulling the cords). The stone continues down and to my right side as I begin to bend my arm and pull it across in front of my body. The stone continues down, now moving to the left, and I release as the stone passes in front of my legs.
Usually, my underhand shots overshoot the target, sometimes by many feet. With this style, I am more consistently releasing the stone in a low, flat, straight trajectory.
Now, if I could get better control of my direction! I am consistently shooting too far to the left...