Get shipping boxes from your local post office. To cut on costs, get the priority-mail boxes which are free of charge and ship at a flat rate. They come in different sizes, so choose one that can accommodate your plant.
Take the plant out its pot and wrap several layers of damp newspaper around the root ball. The damp newspaper will provide the plant with much needed water during transport.
Place the wrapped root ball into a plastic bag. A bag that snugly fits the wrapped root ball works best. It will prevent the roots from being disturbed during transit and avoid root injuries. Tie, tape or wire the bag shut so nothing falls out and the roots are well-contained. Leave the rest of the plant, stem up, uncovered.
Put the plant inside the shipping box and fill the empty space in the root ball part with crumpled paper, making sure that the plant doesn’t shift or move around. Fill the rest of the empty space with packing peanuts. The filler keeps the leaves of the plant from becoming bruised or broken during shipping.
Seal the box shut with packaging tape and take to the courier. Second-day air is best for shipping live plants but if the roots are wrapped well enough, the plants will last 3 or 4 days during normal temperatures.