We have just taken up learning how to fire these, as a kid you just got a Y shaped branch added some elastic bands or knicker elastic (does anyone remember that stuff?) and off you went.
I never realized how far things had moved on, tubes and bands of all different strengths, lengths and thickness, different grips and a multitude of frame designs, fancy wood ones, ornate metal ones, plastic ones and all sorts of other material I have never heard of.
Anyway we are having great fun attempting to hit a target, several broken barn roof tiles and birds flying for cover when they see us coming are an indication as to how good we are! Still it is early days yet!
Currently looking for some Y shaped branches to attempt to create our own and looking for some "theraband gold" exercise bands that are meant to make good slingshot bands. So far not much luck in tracking any down but the search will continue................