I did 'em to mine, as I preferred it over the actual OEM Cobras. The lines were pretty translucent and at times looked too light for my tastes.
The best way to do it (that I found - and I made about 2 dozen sets for people and they all loved 'em) is by counting those little squares you see in the lights. Think of separating them into two sections: upper and lower. The plastic stripe in the middle will separate the two, obviously.
In the upper section, count the number of squares from the top of the plastic strip to the top of the colored lens. Lay the 1/8" pinstripe in the very middle, and that will become your middle stripe. To find where to lay the top & bottom stripe on the top section of the lens, do the same thing. Just count the little squares (I think at this point you'll be counting by halves, but it's still easy and you can almost eye it at this point) and lay the stripes.
To do the lower section, it's the same way. Count the squares, lay pinstriping in the middle, then count up from that stripe to the top (or bottom) of the lens section and lay another in between the two.
One note, though. On the middle stripe on the bottom section, you have to cut it short before it reaches the end of the lens. I can't remember the distance but I believe it's somewhere between 2-3".
Here's the best picture of my car that I could find, that shows the lens striping. You can see how the lower middle (2nd from bottom) stripe is cut short so it doesn't extend all the way to the edge of the lens:
Easier to do than describe, I guess. If you look between the stripes, the red lens that shows through should be pretty much even with the next row.
Other than that, as stated a few times, center the middle first and the others next.
