defining typology lines on reference images

In order to model my own head I have been following a tutorial by Eric Maslowski.
http://cg-india.com/tutorials/3dsmax_tutorials_organic_modeling.html

After taking a picture of my face (front and side) and adjusting it a little bit in photoshop I started to draw typology lines...











Blue lines define general structure of my face..I used wrinkles, and bones as references.
Red lines were used to draw a kind of a net which will make the modeling easier.

The next step was to place the image on a plane in 3D max and draw splines along red lines so they create polygons.