There aree only 3 parts make up of a band, pouch, band, tying thread.
Attaching the bands to the frame The rubber attachment is a vital part of the slingshot: A bad one kills your bands, makes the slingshot inaccurate or can be very dangerous. Be sure to choose one that fits your kind of bands and slingshot.
I think this guy has got the core points of how to make a homemade slingshot band
Very satisfied, I have caught 4 trouts with it. I can pretty much cast as long as with my Aldebaran BFS XG which was 289 dollars!