I take very good care of all my cards, and I expect the same from anyone I trade with.  I always ship in hard case card protectors and bubble mailers via USPS first class.  All that being said, if your grading says near-mint, don't send some busted up card that has obviously been played.  Also, you can ship things to me however you want.  As long as the cards arrive in good shape I do not care how they get here.

The cards that are marked as mint are just so I can remember how many I am not trading and might buylist.  Most of my collection is NM, but older cards might be lightly played.  I can provide scans or photos of cards on request.