One evening at work, I happened to rub my head and got a bit of the oils from my face on my hand. I then just happened to look at my hand while it was backlit by my monitor. I really liked the lighting effect I saw, but I wasn't sure how to reproduce it.
I tried to reproduce it by actually reproducing the circumstances, the result of that was less than spectacular. I finally got the formula right after doing my "see no evil, hear no evil, speak no evil" shots, and noticing I got very much the same effect I was trying for before.
This is shot through a 50mm f1.4 manual focus lens on my D80.
Strobist Info: Just a single Nikon SB600 through a gridded snoot, fired by a Catcus v2s from JUST above the frame behind the hand. A 1/4 CTO gel, and "flash" white balance settings were used.