Take a look at this video from Sensible Prepper, a long-time YouTube user with a ton of great material. He covers a huge variety of uses for a bandanna, everything from keeping the sun off of your neck to tying up a carrying pouch that attaches to MOLLE webbing.
One of the more interesting things about this video is the way that Sensible Prepper shows off his blaze orange bandana which is covered with survival information. Having a bring piece of cloth with you, even without all of the helpful notes, is a great way to signal to rescue crews if you’re lost. Even if things don’t get that dire, bright bandanas make great high-visibility trail markers.
On the other end of the spectrum, Sensible Prepper shows off a lot of the ways that you can use a bandana to evade and escape. His video goes through all of the uses for a bandana around camp, working as a potholder, water filter, tinder, and wound dressing. Sensible Prepper, true to his name, also points out that a bandana makes great one-time use toilet paper.