Soup Hunter Guitars has been building handmade instruments out of other men's trash since 2002. It started with a square solid body electric guitar, moved onto a hubcap banjo, onto some real weird stuff, some electronics, and then it all came back to the last half of the American 19th century.
First, you gotta find some junk.
Cigar Box Guitars are as old as the hills and tend to confuse a lot of modern men. They were built at a time before people used gimmicky words like "supermatic deluxe tremelo" to sell guitars, and by people that didn't want to spend a fortune on an overpriced pile of firewood. It was a long time ago that a lot of folks figured out "It's what you can do with an instrument, not how much you can spend on one". The old blues men knew this, the folk guys knew this, heck, a lot of thoughtful present day musicians know this too.
The best way to pass the time is with some pieces of wood and wire.
Second, you gotta make that junk sing.