I am looking for a figurative or graphic expression to describe the minimal luggage content, fast to pack, or that you always have with you, without which you would feel less safe when travelling. The expression should be concise too.
When I take a plane, and since luggage in the cargo area can get lost, I generally have a toothbrush and underwear. With those, I am not afraid of spending an unplanned night in an hotel in a unknown town.
I would say in my language that I have my "pants and brush", as a short for "a second pair of underpants, socks and a toothbrush", but this does not seem colloquial in English.
In other words, is there a colloquial figurative expression for what one carries when travelling light?