You just do what your comfortable with really. Most folks have tried various methods and found one that they prefer. Kurt's is nurbs for fleshing out then on to poly and sub-d for the details. Some people prefer poly box modeling...others like to build models poly by poly. I prefer the latter two for most modeling, using poly proxy mode so I can have the rough poly and smoothed version side by side for error-checking.
NURBS are cool because they already have their UV coordinates and are very useful/quick for certain things because of their surface tools. Use whatever gets the job done quicker and what you find easier to work with. My .02.
"Terminat Bora Diem, Terminal Auctor opus."