If you do pack the item, pack it well. I was told by SMc, to account for a 5 foot drop, should the shipping container be empty.
With that said, pack your item securely in a box (or in original packaging), then place it in another box with additional packing. This should allow the item to 'float' in the packing should it be dropped.
Freight companies are a different thing and you need to contact them for their procedures.
I recently bought a pair of Vandersteen 2w subs(which weigh about 90lbs each). The seller packed them in the original boxes/packing-no outer packing. They arrived in perfect shape.
For something unwieldy, I would suggest using strapping, but some carriers may not allow it. I suggest visiting their sites to see what is allowed.