My design uses 10mm tubing instead of 8mm, and has 12 rows of neon (plus the two loops at the top) instead of 11. This makes it look much more authentic. The top portion is also curved to fit the torso for a nice flush fit. I use a pretty complex 4 piece design, but I glue the two upper and two lower halves together for easy installation. This also makes it much less fragile than standard neon.
 

Some Pictures: