Labeling plays an important role in shipping and avoid misplacement, mix up or loss of shipment and simplify the process & expedite the transit time.
Shipper (sender) is expected & responsible to mark each package before handing over the shipment to the carrier for transportation. Each box MUST have Ship To address and it's number such as Box 1 of 5, Box 2 of 5 etc.. These labels should be at two opposite side of each box and so as special labels such as Fragile, Direction arrow, Too Heavy etc.
Following is an example to label your shipments.