I agree with Evil Eye. Much improved. Ditch the pure black and pure white. Use the black for another dark brown and adjust the rest of the shades.
Give the character some eyes. They will help define the face, or at least trigger your brain to define the face.
After playing with this, I conclude a 40 pixel head seems to be a bit tough. A 20 pixel head is easier because you only have room for the most important bits. A 64 pixel head is easier because you have enough pixels to do anything (any angle, tilt or turn, subtle curves).
A 40 pixel head is right in between. Not enough room for photo quality shapes, but too much room to get away with simple forms. Or maybe I just need the practice. This is an interesting challenge!
1. Took your last edit, raised the eyes 2 (?) pixels, and the nose 1 pixel. Placed a generic eye socket shape - this is not a good shape, but it will do for now.
Sharpened the chin closer to your original piece.
mostly just hacking at this.
2. Added color, shape. Ended up with a decent face. Not young, but with character. The smile line really helps I think.
The eyes have changed shape, mostly by raising the outside corner one pixel. In retrospect, I think I like this face and should have stuck with it.
At 1x there is just not enough contrast
3. But why not simplify and try a younger face? Erased the smile lines, softened the jaw, shrunk the cheeks.
Redid the eyes a bit. Much better I think.
Much wrestling with the mouth. I don't like these colors - there's a big jump between mid and the mid-dark which makes it tough to add any curves to the lips.
Similar problems with the nose. Not quite enough pixels to get the curve right.
4. Playing with colors
5. More playing with colors
6. Then the muse grabbed me and would not let go. Sigh. All I wanted was to add a little red to the lips and pink to the cheeks, test out a new color picker. But no, the muse was not satisfied. Still isn't, truth be told, but at least it let go.
The main problem is that all the lines (cheeks, jaw, nose, shoulders) point to the chin, which is altogether uninteresting. I guess this should count in the list of things to avoid.
Tourist