I finally bought a scanner so my list of excuses for not uploading my drawings is dwindling Here's a quick tutorial I put together.

Supplies I used here:
Copic Ciao Markers, YR31, YR23, E35, E47, W3
Copic Multiliner, sepia
Sakura Gelly Roll Pen, white
Copic Bleedproof Marker Pad paper

Tips:

Use the brush nib end of the marker for the nicest blending

If you want smooth colouring, move to the next step before the Copic ink dries. Alcohol evaporates quickly so move fast!

For a more cel-shaded look, let the ink dry completely between each step

If the ink is drying too quickly, you can usually get away with doing a second layer with the same or a slightly lighter colour to keep it wet, before moving onto a darker colour

If you don't have an alcohol-proof ink pen, do the inking last

Make sure the white ink/paint is completely dry before going over it with your marker

You can finish at step 8 if you like the pretty anime "cataract" effect, or go on to step 9 for a more focused-looking eye

http://artichokes.deviantart.com/art/Copic-Eye-Tutorial-583729944