"wrap and tuck method" illustrated here. I did not think that this method would work very well, but it is incredibly solid. The bands will likely break in 1/2 before the wraps come off, or even move for that matter!
Now it makes sense to carve the front of the forks flat (the side with the bans attached) , that will keep the bands aligned over the top of the slingshot, and prevent the bands from creeping around the sides of the forks over time. Although I see no signs of this happening!
I was thinking that using the rubber bands for this was a bit ghetto, but I came across some threads last night where it seemed that some folks actually prefer this method to more expensive alternatives like using exercise bands cut to size. The main thing in choosing rubber for this seems to be that it pretty much has to be latex.
I am stoked, this thing will cause a dry chickpea to produce a satisfying clang on a streetsign from across the street. With anything heavier like a pebble or a ballbearing would be alot more accurate. Looking forward to shooting indy rock fans this weekend @ All Tomorrows Parties.