creating a head from NURBS curves
 

I would like to know any trick to prepare the curves needed to match the model of a head.

I´ve been taking as reference the six patches method of Andrew Camenisch, that provide less distortion over seams.

I normaly use polygons as starting point, but this technic with NURBS attracts my attention a lot, and could be good for certain head models.

http://www.boris3d.de/tutorials.html

Look for the tutorials on nurbs patch models. Specifically, the ones for faces. I knew a lot about patch modeling, but I learned a lot really quick when I read through a few of these tutorials. There is one tut about patch modeling a dino face. If you read through it, you will find that the basic outline of each patch was drawn before the other curves were added. This is very useful I think because you get the basic shape of the head before you begin adding intricate detail. Don't create all the curves at once. Create a few (the outlines of each patch), model a little, add a few more curves, model a bit more, then add the rest. Then you can perform the final loft.

Watch the VIP Nurbs Shark Tutorial, that should give you some pointers.
Also, if you can get to view it, Gnomon Workshop´s Organic Modelling video can help you a lot too.

I´ll take a look to these tutorials.

Thanks