In this technique we first create a low detail head by nurbs patch modeling then convert it to apolygon object, then we add detail to it. The reason is that we have more control on the basic shape in Nurbs modeling and then we apply powerful tools in polygon modeling to add details. You should know the basics of modeling in Maya to do the modeling technique in this tutorial.
First create two planes in Front and Side view then project the images onto the planes as reference. You can find many high res reference photos at www.fineart.sk
Draw the front and side profile of the head.
Then draw the curves that define the eye, nose and mouth and connect them.
After drawing all the curves, select them and cut them from the intersects.(EDIT CURVES>CUT CURVE) Make sure to cut every curve, then Rebuild them.(EDIT CURVES>REBUILD CURVE) -use default setting Start creating surfaces by selecting four curves (hold SHIFT for multiple selection) and apply Boundary tool. (SURFACES>BOUNDARY)