Here is a site with very good directions for making these.


http://www.valleyviewmarket.com/glass-lights.html



they are not something i have fooled with yet - many others in my area make them, so i do not - they sell for 25-40 each, depending upon what the market will bear and how elaborate you go with the decorations... you can also find pre-drilled blocks too for more money, but less hassle...