I used some of these packing cubes on a recent trip to Europe.  I found I could easily pack underwear, socks and rolled t-shirts in these -- it made packing so much easier!  These are light but made from a strong material so I could really stuff them full.  When we arrived at a new place, I just pulled out these cubes and put them in a dresser drawer and put my suitcase into the closet -- it made me feel settled in much quicker and made it easier to pack up when we were getting ready to go.  I used this with Rick Steves' Convertible Carry On -- a good pair.