I have been changing the way I do eyes alot lately. (Trying to find my own style, ya know?) But this is how I do it right now.
Step 1: Use Gradient
Step 2: Make the Pupil a bit darker than the dark shade of the gradient and put it in the direction of where the person is looking.
Step 3: Make the highlight (a mix of the light gradient w/ white) with an airbrush.
Step 4: (Not Shown) Add the Eye Strokes(don't know what they're called) by using the smallest pencil size and coloring on divide.
Step 5: Add White Highlight where the light is the brightest.
Step 6: Blur it all in. (Especially the Eye Strokes.)