Since I had cut open the groove for the keyring, I had to drill another hole near the edge of the key head. Don't make it too close to the edge so that the key's structural integrity is kept relatively intact.



Also, think about what side you want the keys to hang from (while you're opening a bottle and while you're using the key). I didn't want the keys flopping all over the top of the bottle, so I drilled the hole on the same side as the tooth. The keys hang nicely along the side of the bottle.