Think about packing a wide mouth travel mug in your carry on bag. Make sure it is one with a screw on lid.
Use it for the obvious…water or coffee or tea. But, it can serve a whole lot more purposes than just liquids.
Transport your sunglasses in it…they won’t get crushed. Pack delicate souvenirs to bring home. Store your extra cash in it in the bottom of your carry on bag. Keep your cords for your travel gadgets in it. Toss the extra change in it so it doesn’t weigh down your pockets.
If you’re traveling with kids, put their crayons or markers in it. You can even roll up some drawing paper and put in with the crayons. Or, put their snacks in it so they don’t turn into crumbs.
I’m sure there are plenty more uses…what do you do?