When it comes to packing for longer or multi-destination trips, you'll likely be using a wheeled suitcase (sometimes called a rollerboard). You're not going to look cool rolling it around so at least take advantage of help it provides. "The heaviest items should be down on the wheels," McAlpin says. "It makes the bag easier to roll." That means things like shoes and books go on the bottom. Packing this way is also better for your shoulders and an extremely good idea for men with back troubles. The advice holds if you're carrying a duffel because dense items are likely to dig into your side.