When loading a truck or a storage unit remember the fundamental rule of stacking as high as possible. If practical load items as high as you can reach, especially when you start loading. As you fill your truck or storage unit you may determine that you don’t need to pack as high as you did initially because you are running out of items to store or move. Until you get to that point, continue to stack as efficiently as possible.
Start stacking with heavy weight items on the bottom (like larger appliances, heavy furniture, books, etc.), then medium weight objects (like small furniture and not so heavy boxes) and finally the lightest weight items (like cushions, boxes of glass, boxes with plants etc.) on top. When moving with fragile items make sure these things are stored in a stable location. In a truck remember there may be hard stops or hills to climb and stuff on the top may shift.