whereas our upcoming trip on the fantasy will be our first carnival cruise with our children, i have cruised before. besides the obvious items to pack (pants, shirts, shoes), the 5 must haves for our family are as follows:
-a large cup (ours are those bright colored cheap tumblers from walmart-usually a $1 or 2 for a pack of four).
-small container of some sort of laundry/mild soap to wash out small items in bathroom sink. laundromat type room is available but its crazy expensive.
-batteries (AA, AAA, whatever your camera needs...bring more than you think you would ever need).
-e-reader device (we have kindle).
if you have kids:
-small amount of entertainment for the children (a couple toys, coloring books, etc).
hope that helps. i thought about not putting any explanation or reasoning for items, but if did that, i sounded kind of like some sort of macguyver and/or deviant bent on corrupting the young. i assure you, i do not corrupt the young.