Old examples of slungshots are hard to find, so I made one myself. It's kind of crude, but it's cheap, quick and historically interesting
Google for monkey's fist and you should get some good types and tying instructions, a real old school piece of nastiness - I used to make them with a large glasss marble inside when I was a Scout many decades ago.
Slunshots are banned by statute in many US areas they mean what I thought not what you thought - have a look at a man called Don Rearic's website to see more on the subject, he knows much more than me.