I like to bring a small sewing kit and extra safety pins, an over the door shoe organizer that's clear. I put batteries, hair gel, spray, suntan lotion etc. Anything that would usually be on a counter. The cabin stewards love them. Highlighter pen for marking the daily schedule to make sure i don't miss an activity. A small first aid kit with extra bandaids. Cold medicine and Tylenol as they are quite expensive on the ship.