After 25 years in the Air Force, I have had a lot of experience with packing
shells.  I even let the "professional" packers to the job the first couple
times.  I ended up with a 10 lb piece of coral packed on top of a bunch of
murex.  It was amazing how many were not smashed.

I then started to always pack my own.  I use dish packs for the boxs.  This
is a box that comes with inserts to devide it up into small sections as well
as inserts that devide it into layers vertically.  They work great and are
well worth buying.  I start with each shell in a plastic bag and then wrap
that in tissue (toilet paper works great).  This package is then wrapped in
moving paper (like newspaper without print).  Small shell are wrapped with
several tissue wrapped shells together in a single newspaper wrapping.
Larger shells are wrapped with bubble wrap and then the newspaper.  I put
the larger shells on the bottom  - not because they would crush the smaller
shells as the verticle partions prevent this - but because it makes the
boxes easier to handle.  The newspaper seems to pack really well and
provides great protection.  Any open spaces are filled with wadded up
newspaper.  In some 20 moves using this method I have yet to have a single
shell damaged (except the couple I dropped when unwrapping them).
Unwrapping is a huge mess, but very much like Christmas - only who among us
has had a Christmas with all shells!?

Tom Eichhorst in New Mexico, USA