I cut off short pieces of old garden hose to jam onto the antler tips. Use a well fitting box, and make sure the antler doesn't move around by taping the antler to the inside of the box with packing tape and wadded up newspaper. Most people just throw the antler into a box full of packing peanuts, but they're messy, and they always show up with points poking through the box.
I want the biggest one.