Because half of a bandana cut diagonally will do every thing a whole bandana does, I cut my bandana in two. I, however, end up bringing both halfs because I have incompatible uses for them. I cut or make a button hole in one end so that I can loop it to the outside of my pack, or around my neck. This system works a lot better than tying it on. I haven’t lost a bandana since getting the button hole put in it. If you don’t hem it, it will get pretty ratty looking.
And because a bandana makes a lousy wash cloth and a terry wash cloth makes a lousy bandana, I cut a small light terry wash cloth diagonally, and put a button hole in it too.
Note: I don’t like the look of the standard bandanna, so I made my own out of a scarf.