Here's a list of cool and neat ideas on what to bring on a cruise.
Clear plastic over the door bag – You can hang it over the outside of the bathroom door. You can find one in Walmart. Just make sure you get the clear plastic ones so you can see through and easily find small things.
Duct tape – away from using it to tape things, you can use it to mark your luggage, for repairing stuff and using it as a lint remover.
Air freshener – very important for the bathroom because you'll never know what just happened a few minutes ago.
Small lines and clothespins – Staterooms / suites can be a damp when there are wet clothes all over the tub and shower. You can just hang it low so the view will still be good.
Ionic Breeze – if you're traveling with someone who is sensitive to recycled air, then you need to bring this along. This will provide instant fresh air and relate someone of their sinus problems.
Small flashlight – if your room is small, a small flashlight will help you to get around more easily and avoid falling over someone.
Phone cards – you can give these as gifts to cruise employees. Some of the employees are from other countries and sometimes it's tough for them to spend their hard earned money just to call home.
Candy bars – you can wrap your dollar tips around the candy bars when tipping your stewards, waiters, assistants and other crew members. It's really fulfilling to see the smiles from them when they received this unexpected tip.