This window has 290 pieces of glass and will use several types and colors of glass. Making sure that each individual pattern and glass piece has a unique number is essential. Keeping pattern pieces organized is equally important. After I cut each piece of the manila folder pattern, I placed them into envelopes labeled with the color and type of glass. As the glass pieces are cut, I put their individual pattern pieces into another envelope marked "cut", so that I can readily keep track.
Here's a look at the pattern pieces laying on top of the glass, during and after cutting. I do them production-line style, cutting similar pieces at once. Shown below is the grape rough rolled glass. (I mark all darker colors with a silver Sharpie pen). After each piece is cut, I grind the edges with a grinder. (My most recent commission, an octagon window, shows this process in more detail).