Me again!

I'm moving house. But the detail of where to and when is up in the air.
Everything is going into storage while I travel a bit, for a month or two or
a year or two. I know the topic of shell storage is not a new one. What makes
this different is I need to pack them to withstand impact and shipping, but
for a potentially long duration. I was thinking of plastic boxes and tissue
and cotton. Any materials I should avoid?

Thanks, in advance, for any suggestions or warnings.