Packing well isn't easy or fun, but it's a lot less stressful with packing cubes. Like mini modular suitcases, they make organisation simple and are your best ally in the fight to keep your suitcase user-friendly.
I love packing cubes. Travelling with a suitcase was always an extreme frustration before I finally decided to give them a try. You can always try to pack more effectively, but many of the great packing techniques unravel the moment you start unpacking your suitcase. Packing cubes are little modular compartments you can use to separate and organise the items in your suitcase so you don't have to worry about anything getting mixed up when you unpack - or worse, when the TSA decides to search your suitcase and makes a mess of your hard work.
Packing cubes are nothing new, but most people ignore them for a few reasons: they seem like an unnecessary expense, they're too expensive, and they're just for clothing. While there are certainly a lot of overpriced packing cubes, you can generally pick up a full set for less than $US30 at Amazon or eBags. They're also extremely useful for more than just clothing. If you read Lifehacker there's a good chance you travel with a lot of technology, and these packing cubes can be immensely useful for keeping all your cables and charges in one compact location. You can use them for practically everything you travel with and it makes it much easier to find things and unpack. You can just move the packing cubes into drawers in your hotel room when you arrive so your items can be easily re-packed when you leave. It also helps to travel with a spare cube for dirty laundry on the way back.
The bottom line: packing cubes are a huge help when you travel and I highly recommend giving them a shot.