I take a collapsible nylon mini-duffel, empty. We use it for whatever we buy in ports that might be too fragile to pack in a regular suitcase. I also bought one of the expandable carry-ons from Carnival some years ago. Getting on the ship, it has my jewelry, med's, camera, etc. Getting off the ship, I unzip it to its full height for the last morning stuff. It has wheels on the bottom and the height and handle are just long enough to let me roll it. But, in ports, I use a nylon backpack for anything I might buy.