I don't really know how to, but I would recommend that you don't make one using wire. If a buck that isn't ready to drop his sheds uses it, he could get stuck. I would guess that you could make a small box with feed in it, then make something like salad bars at resteraunts with the plexi-glass around the top. This way bucks would have to work there heads in there, if their antlers are loose, it will knock them off, it they aren't ready, then they won't get stuck.

Good Luck This Season: Buck Magnet
P.S. Only Chuck Adams can sit at home and see deer so get into the woods. =;^)