Whenever you travel away from home, always take a few rubber elastic bands with you. They are small and light, but you will find a use for them more often than not as you travel!
Like the time I was in Greece and the shower had a flexible cord with a handheld shower head, the type that fits into a bracket when you’re not holding it. Except the bracket was broken and didn't hold the shower head. Out came the trusty elastic band and presto, shower temporarily fixed.
My elastic bands have temporarily solved all sorts of problems, from holding shoes and bags together, to opening jars that just wouldn't budge (fit the elastic band around the lid for extra grip). They also keep cords and cables tidy when packing, and if you travel with a bunch of germ-o-phobes, an elastic band around the sick person's glass or cup makes everyone else feel less stressed, so they don't use the "germy" one by mistake.