It took me a long time to invest in packing cubes. For one, I was using Hefty 2.5 Gallon ziploc bags to great effect (you can squeeze all the air out) and for two, these are expensive. However, I finally purchased the Eagle Creek lightweight packing cubes. They are expensive, but they are very good. I'm a total fan now. It really does help keep everything organized. I also purchased some heavier-weight Bagail brand ones from Amazon that are good and come in a variety of sizes. Eagle Creek lightweight would be the gold standard due to the weight and the material.