Read the answer here!
I start enveloping your model in a air bubble sheet...
...closing it with adhesive tape
I take the box. I always use new boxes of hard cardboard. I made a thick layer of "packaging curls" ( I do not know the name of these stuff) and I put your wrapped model inside the box.
Another upper layer of curls...
...and I close your box with strong packaging adhesive tape. I glue the label with your address (I've removed it from the image for privacy) and cover it with transparent adhesive tape to protect it.
The box is ready!