I've become interested in hammock camping lately. I was inspired by Shug, a YouTuber who hikes and camps with a hammock and has mastered the art of enjoying himself in the woods.
There are a lot of ways to hang a hammock. The crazy array of options is pretty confusing at first, but I think that's actually part of the appeal. Picking your system and dialing it all in is exciting and makes the experience more personal.
One of the most baffling items, and one that comes up a lot, is something called a whoopie sling. In videos and diagrams it just looks like a funky rope. It's not clear what it even does. I eventually figued it out. It's really just an adjustable length rope with a loop on each end. You use it to connect some kind of tree strap to one end of your hammock. You can make one by tying a few knots in a hollow-cored rope. People generally use 7/64" Amsteel rope. The adjustable length is achieved by looping one end of the line and running it through itself, creating what's called a bury. When you pull on either end, the rope around the buried section contracts down and binds. It's the same mechanism by which a Chinese finger trap grabs a finger.
When I was making my own, I kept looking for a good diagram. The construction is really simple when it's in your hands but a bit confusing on screen. I couldn't find a good diagram, so I made one. I hope it's helpful!
I also made one for a continuous loop, which people use to bundle up the fabric of their hammock and create a loop to connect to.