Basic rule of thumb – pack light items in large boxes and heavy items in small boxes. The heavier the box the harder it will be to move. Pack no more than 50 pounds per carton. Don’t over-pack a container, even the small ones. Don’t make them so heavy they’re difficult to lift without straining. And always remember - lift the box with your legs, not your back.
When packing a box place large, heavy items on the bottom and lighter, more fragile items on the top. Group items of similar size and weight. Separate the items with bubble wrap or packing paper to prevent scratches caused by rubbing. More information on house move here.
Pack boxes to the top. This prevents them from being crushed when they are stacked. Fill each box as much as possible using crumpled packing paper, bubble wrap, towels, pillows and blankets to fill empty space to prevent shifting and breakage. Make sure tops and sides of boxes do not bulge or sag. Under-packed boxes may collapse and over-packed boxes may rupture.
When packing small fragile items wrap each one individually with packing paper or bubble wrap.