The book I'm trying to find I read a few years ago. As far as I can remember, there's an elf who has tattoos somehow attached to his magic. I remember a piece of the book where the other main character, the female, had re-tattooed one for him. Not much to go on, but that's about all I remember.
Could this be the DragonCrown War Cycle series? According to Wikipedia:
The DragonCrown War Cycle is a four book fantasy series consisting of a prequel, The Dark Glory War, and three main volumes, Fortress Draconis, When Dragons Rage, and The Grand Crusade. The books were written by Michael A. Stackpole and published by Bantam Spectra, a subsidiary of Randomhouse inc. over the course of 4 years from 2000-2003. The books follow a group of heroes as they struggle to bring to fruition the Norrington Prophecy, so that they can defeat the evil Queen of the north, Chytrine, and save the southern kingdoms from destruction.
Another question says "there was a warrior elf with magic tattoos that glowed blue".