Well, I have a program called CutStudio that I design the graphic in and then I plot it to a vinyl cutter.
After the vinyl is cut, I stick the pieces on the glass how I want them and tape off any areas that I don't want etched.
Then I go to my trusty sandblasting cabinet and huge compressor unit and sandblast the piece thoroughly.
It is really quite simple once you have the equipment... the stencil/vinyl placement can be tricky though. you have to make sure there are no air bubbles and on curved glass with curved stencils proves to be quite annoying.
I hear you can do this with a dremmel with diamond tips but have yet to try that.
I hope this helps. I really appreciate all the kind words.