Tonight we made glasses out of old beer bottles we had around. We tied some fingernail polish remover soaked yarn around the bottle and lit it on fire. Then rotated it to burn evenly for about 20-30 seconds then dipped it into a sink full or cold water. It usually broke on its own, but some times needed a little help. It didn’t always break evenly or exactly where I wanted it to, but I kept trying. Eventually we got a few that were good. Then I sanded around the top with sandpaper to get rid of any sharp edges. They’re pretty snazzy little cups.