This may be the most unconventional item in our cruise kit...trash bags. We use them to line the laundry bags. The bags for "free" laundry or "half price" laundry are flimsy, thin paper, and you're limited to what you can put in the bag.
By lining the bag and rolling the clothes, we can fit in 20-30% more items. I'll show you the result on our first laundry day.