After my wife and I decided that I would build a  custom art glass panel for her sister's wedding present, I began looking through my books and searching the internet for something suitable.  After emailing a few samples, she decided on a pattern and colors.  The advent of email and digital images on the internet made this part of the process relatively simple. 

Another aspect of the process that's been made easier by the ubiquitousness of the  computer is development of a software programs that assist in drawing the cartoon -- the full-scale line drawing of the piece.  I used Dragonfly Software's Glass Eye 2000 program to draw the color version of the panel and produce the two cartoons need to cut and build the piece.  This is all so much easier than when I was more active in glass back in the early 1980s.  Back then it was draw by hand and copy on a photocopier or trace on tracing paper.  Glass Eye 2000 is actually a CAD program that's been modified to deal with the idiosyncrasies of curvilinear glass shapes, glass colors & textures, and the various shapes and sizes of lead came -  and it does all of this very well.  
 

With an April deadline, I began the project in February.  Since it was a bit cold in the shop, I set moved into the bright and warm Breakfast Room. As the weather improved I moved to the shop to perform the messier jobs of grinding, soldering, and puttying.

The cutting surface I used was low-nap indoor/outdoor carpet glued to a sheet of 1/4" Masonite hardboard.  This provided a soft, yet firm, surface for cutting glass and it also allowed glass shards to drop into the nap and out of the way until vacuumed off.  I clamped this surface to the breakfast room table, which is actually a maple work table 8from Williams Sonoma. 

The work surface is a sheet of plywood with two ledger strips attached at a right-angles to one another.  As you can see, this is clamped to the Workmate in the corner of the room.  For a normal square or rectangular, panel you start building from from the intersection of the ledger strips and work outwards. For this project, I referenced the bottom of the glass panel off of the lower ledger strip.  Note the paper "cartoon," on the building surface.  This cartoon is a duplicate of the one cut up and used as a pattern for cutting the glass.  The cartoon on the work surface serves as a guide to keep the pattern from "growing on you."
 

Here, I have laid out the already cut glass pieces on the work surface.  The cutting patterns are still affixed to the glass with contact cement.  The cartoon that serves as a glass cutting pattern is cut to size using a special pair of scissors called "Pattern Shears. These shears have three cutting fingers, which causes two cuts to be made when using them.  The end result is that a small sliver of paper is removed between cuts leaving a space for the "H" shaped lead came to occupy.  The next step from here is to begin the leading process.  Some glass grinding is necessary to keep everything in alignment as the panel goes together.
 

In this photo, I am almost finished soldering the lead came joints. The glass panel has an 18 1/2" radius, which makes it about 37" wide. 

An interesting bit of trivia (at least to me) is that stained glass is one of the few common uses for horseshoe nails - other than horseshoeing of course.  Because horseshoe nails are rectangular in cross-section, they are ideal for holding the glass and the came tightly in place against the ledger strips as you build outwards. A round nail would put too much pressure on a very small spot and probably crack the glass. 
 

This photo was taken in the middle of the clean up phase after soldering was completed and glass putty was forced into the gap between the lead came and glass.  The putty serves to weatherize the panel, as well as  to stiffen and stabilize it.   This putty is a traditional mixture of boiled linseed oil, whiting (calcium carbonate), plaster of Paris, lampblack, and turpentine - mixed to taste.  The whiting you see sprinkled on the glass serves to soak up any oily residue as well as to polish the glass as I scrub it with a stiff brush. 
 

Here, the completed window panel sits propped up in the shop window, serving as inspiration to move on to the frame building process.

Again, the panel size is about 37" wide x 18 1/2" high.