Forgotten your tweezers and have an emergency on the road? This is a trick that I learned from Chinese gents in Singapore.
Grab two coins and hold them together. Slide them until they grab the offending hair and then pull gently. It takes some getting used to, but it works for that odd hair that can crop up (or out!). Obviously you aren’t going to be able to shape eyebrows with them, but they’re good for that one or two strays.