As with all these tutorials this is how I approach my work and shouldn't be considered the only or best way of painitng, rather it's just another option. But I hope these are bringing an insight into how I paint and to give you something new to try.
Today I want to mention the colour of eyes: I normally paint the whites of the eyes in either a flesh tone (Vallejo Light flesh normally) or GW Space Wolves Grey as I find pure white is way too stark. I then allow some GW Ogryn Flesh to pool in the edges around the eye lids. I've found doing things this way I get a much more natural looking eye.