For my most recent cruise I decided to test out the 4 piece packing cube set. They made packing so much easier. I was able to separate t-shirts, pants and other clothing items and even used the smallest one for all my cruise essentials.
Each one will stretch so you can put a lot into each one and has strong zippers allowing to close easy. On the top, they are clear mesh so you can not only see whats in the cube but it allows air to circulate.
I was able to fit 3 into a 21 inch carry on with no problem.
Check out the link below to get yours before your next vacation. They do come in a variety of colors.