Hi Anil,
I have used this tut (and found it really useful).
https://www.geocities.com/susantio/head01.htm
Hope this helps.
Feel free to contact me here at Simply Maya.
Here is a link to one of my WIP using SubD. The second page has some info re edgeloops etc..
https://64.4.30.250/cgi-bin/linkrd?_l...goto%3dnewpost
Re Jim
Mayan elder......only in years.....