What's the best way to pack and ship fragile valuables?

If I want to move some valuable breakables such as china and glassware, am I better off packing them in large plastic boxes or cardboard?

Assume that they are well packed in bubble wrap and that they will be loaded by professionals and taken with other items in a moving van.

Or should I transport them by some means other than a moving service?

Should I even try to pack them myself, or should I get them all together and have them packed by pros?

The quantity is not large, but the value is high and the objects are irreplaceable.
 

Tags as I wrote them: moving, transport, china, heirlooms, glassware, fragile items, packing and shipping, Limoges porcelain. I did not put a capital C on china.