One of the most popular videos we’ve ever shared on Make: (see below) is of Dan Rojas demonstrating how to cut a wine/beer bottle very cleanly using only a light score line and hot and cold water to stress the score and separate the glass. In that video, he uses a conventional glass cutting jig, which will cost you from $20-45. In the video, Dan talks about building a cutting jig in a future video, but as far as we know, that video never happened. There are a number of tutorials for building such jigs online. I like this simple adjustable one that I found on Instructables that uses only a few pieces of wood, some bolts, and the head of a glass-cutting tool that you can pick up for a few bucks.
I bought some beautiful recycled drinking glasses for a family member last Christmas. I was shocked at how expensive they were. With this rig and Dan’s technique, you can make lots of cool glasses for next to nothing.