I've used Rick Steves packing cubes in the past.  They are deeper than these cubes, but they are made of mesh and I've had problems with the mesh tearing and with the zippers.

These cubes have some mesh on the top so you can see what's inside, but the sides and bottoms are made of a nylon fabric that seems much more durable.  Two of the eBags medium cubes fit perfectly in the bottom of a carryon bag. I hate packing and repacking a bag without cubes.  Now I organize each cube by type what's in it, i.e. shirts, underwear, pants, etc., so it's easy to find whatever I'm looking for (and to check whether I've forgotten anything!).  To repack at  the end of a trip, just throw the cubes in.  These cubes have simplified my life when traveling!