Instead of digging through dumpsters for cheap boxes for which many become too small or not a good fit, purchase your boxes in bundles. Stick to 3 sizes and label them accordingly. Don't pack anything you don't use, set that aside. Get the important stuff, and fill up boxes. Try never to pack books and weight lifting equipment in boxes filled to the brim. Make sure the box is strong enough to hold the weight. Leave a little room and other items, but fill up the boxes for regular personal household items, don't leave them half empty for household goods, clothes, and delicate treasure items. Label the box fragile if it holds one item. Use peanut packing materials in the box for shifting and cushion protection. Its worth it.