I came up with this technique while designing a glass art logo. The results were pretty nice so I thought I’d share. This is written in Adobe Illustrator CS3 but it should be fairly simple to implement in other programs.

1. First, create the basic shape using the pen tool:
   
2. Next, slice it into chunks using the knife tool:
   
3. Third, select the chunks with the direct selection tool and color them separately:
   
4. Now select the whole and change the transparency to “Overlay.” Use the direct selection tool to select the edges of the sliced pieces and “stretch” them to create the color overlap.
   
5. Give the whole piece a Diffuse Glow. I’ve included a screenshot with the settings I used.
   
6. Copy the object and apply a white to black radial gradient:
   
7. The gradient is being used to create highlights where the light is shining. Finally, after it’s set, align it over the original shape and reduce the transparency. I used 6%.
8. And you’re finished! You should have something resembling the pic below: