I'm with P and ToD on this. Eyes are a pain in the ass*, and if you don't need to do them, then dont. If you absolutely must do them, try this:
1. paint the rest of the face
2. carefully paint in the whole eye with a pale bone colour. Use your pointiest brush for this.
3. carefully use a dark brown ink/thinned dark brown paint to outline the eyeball. You shouldn't need to paint this in, per se - just let the liquid flow around the eye. If you get the right amount of paint/ink on the brush, it should be relatively straightforward. If you get a bit on the eyeball, that's fine. It should be thin enough that the eyeball still looks light compared to the surrounnding skin.
4. Dot in the pupil using a dark brown or dark grey paint. This this a bit to help it flow. As previously mentioned, make sure there is no white showing above or below the dot.
5. Tidy up around the eye where you inevitably got some bone/dark dot colour on the eye socket.
Hope that helps. Generally, though, I don't bother with pupile (but then I mostly paint evil night-dwelling aliens and goblins, and who says they need pupils anyway?)
ps - pupil dots give the eye direction. make sure both eyes are pointing the same way - this always gives me trouble...
*sounds a bit Tzeentchian...
