FWIW, from my limited (but successful!) experience shipping glass:
Preventing energy from reaching the glass is crucial. (this might seem obvious, but as a buyer of glass, I can tell you it's not!)
My method:
The glass should ship vertically, this is the strongest orientation that glass has, as it minimizes flex.
Make a wooden frame for it, perhaps out of 1x3 or 1x4s, assembled so that it is 3-4" wide. Put some wooden gussets in the corners. Put some vertical 1x3s top-to-bottom (1 or 2 is enough).
Get plumbing pipe-wrap insulation, and put it around the edges of the glass.
Size the crate so that there is a few inches of space around the glass.
Affix dunnage in the crate so that the glass can bobble around just a little bit. That's how the energy gets absorbed.
You do NOT want the glass held so tightly that any bumps to the crate transfer the energy into a rigidly-held piece of glass.
You do NOT want the glass so loose that it can have collisions inside the crate from normal handling.
Just a little bobble is all.
Then skin the crate sides with double-wall corrugate or 1/4" plywood. Try to do this in a manner that it angles inward at the top, as this makes the whole 1x3/1x4 top board turn into a good grabbing feature. There's no point to making a good shipping crate if it gets dropped constantly because people can't grasp it effectively.