Here's what's worked for me: Wrap with paper and put a 1/8" hard board (or two pieces of thicker cardboard on each side) that extends at least an inch past the glass on all sides against the glass and wrap tightly with tape or cling wrap.
Then wrap that in bubble wrap, and then box it up with at least 2 inches of packing around all 6 sides -- in something that won't shift like peanuts allowing the inner piece up against the edge of the box, so taped bubble wrap instead of packing peanuts. Use packing peanuts only above/below the item in the outerbox, not as edge protection.