You might want to look for Balikbayan boxes. Filipinos have a custom of bringing back gifts to their friends and relatives in the Philippines and make full use of their baggage allowance to do so. If you see the check-in line for a flight to the Philippines, you'll usually see long lines of people with two of these boxes each.
These are just standard cardboard boxes, though some are sturdier than others and usually conform to airlines restrictions. When my parents bring these boxes back to the Philippines, they usually wrap it very carefully in packing tape, usually use rope, as well, and put the recipient's address on all sides. However, if they're pushing the weight limit, they'll leave the top untaped in case they have to pull stuff out at the airport. Their scales don't always agree with the airport's scales. They also make sure to bring packing tape with them to the airport.