Character Creation - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 131

Lips
The same technique is used to add some definition
to the lips. A single loop cut is made around the
mouth, between the loop of edges that make up the
lips and the next one out. With that new loop
selected, activate Edge Slide ( Ctrl-E ) and move that
loop toward the lips. As you get closer, you will be
able to see a nicely defined, though still smooth,
edge appear in the subsurfaced mesh.

This demonstrates a general rule for working with
meshes that will use a Subdivision Surface modifier:
To “harden” an edge and add definition, add a loop
cut and edge slide it toward one of the existing
loops. Figure 6.8 shows a before and after of the
technique.

Eyes and Eyelids
In order to create eyelids and to get the correct shape
for the geometry surrounding the eyes, you need to
actually add eyes. For almost all natural characters,
eyes are spheres. For test purposes, you can simply
add a UV Sphere to the scene, scale it appropriately, and move it into position. If you like, you can Append
a finished eye object from the Web Bucket file eyeball.blend . This object includes all the surfacing needed for
a good eye. When you place the eyeball within the head, you will probably find that the mesh surrounding
the eye is not a good fit. Remember that you must make the head conform to the eye, not the other way
around. Nonspherical eyes will not rotate properly. Whether you choose a placeholder sphere or the appended
eye object, the new goal is the same: fit the geometry of the head to the eyeball.

Figure 6.5 Some areas that need additional detail.

Figure 6.9 shows the rough
head with eyes in place.
Notice how the inner portion
of the opening for the eye
leaves a large gap, and the
outside edge disappears into
the eye. Some PEF modeling
and fine tweaking will remedy
this into the “after” shot of the
figure. Keep in mind that this
may change the look of the
character. So what does this
mean? First, it means that your Figure 6.6 Adding geometry via a loop cut and adjusting the contour.