Here's an outdoor hack I'm going to have to try in the field: creating rings from split branches. I know, that hardly sounds exciting. But as this video shows, you can do quite a few things with these small hoops. Specifically, it shows them being used to: (1) to keep a plastic bag's mouth open, (2) to assemble a tripod and (3) to hang the open bag from the tripod. Here's a screencap of the tripod setup:
While not a true field test, I did pick up some branches at the end of my trail run and today fiddled around with making some rings. I was actually able split the branches using the P-51 can opener that lives on my keychain:
However, I failed to actually construct the rings: I think the wood I picked up was just too dead and dried out to be pliable enough to for the job. Still, with practice, I could see this working.
Here, watch the video below. It's far from exciting stuff, but it's the kind of complete demonstration that's actually useful for learning a new skill.