WARNING: Long and Narrow.
Okay, I decided to just do a quick cel shade cg tutorial on eyes....specifically Fujioka Haruhi from Ouran High School Host Club, because that was the picture I was working on and I've already having a collection of Hikaru and Haruhi artwork I'm making bwahhaa....Anyways...
Er, it is not really a tutorial, just some steps I take to making the eyes. Hope it help in some way or another. Also one more big tip: THINK SHAPE! When it comes to shadow and highlights, its all about the shape.
EDIT: Just correcting my English...Thank for pointing them out ahaha.