Packing cubes are a frequent traveler’s best friend. They work best with backpacker luggage of course, but are just as good for duffle bags or regular suitcases–in particular carry-ons. They normally come in a pack of different sizes: Small, medium and large. It just makes organizing neat and quick. Makes the utility of space in luggage possible and finding articles in a hurry no problem. I can’t leave to travel without them. The ones I have are from ebags and have had them for a few years. Makes packing less stressful and so easy its not even a chore. The cubes themselves zip around resembling a set of drawers or boxed organizers with mesh on top. I know suctioned plastic bags are popular as well though I have never used them myself and they seem too much trouble. The meshed packing cubes should be as efficient as the suctioned ones anyway without the hassle of suctioning.