are there any video clips that show how to properly serve and double serve?  If not then is there someone on here that would be willing to post one?

There are a few on youtube. that I have watched.

The link is below.

http://www.youtube.com/watch?v=G1Koj0wmLg0

I double serve when I making some 6 strand 450+ strrings.I first serve with a No.62 .018 and then I serve with a No.62 .021 over it.But I only serve the .021 just enough for where my fingers grab and for the nocking point.I serve the .021 over because it is wider the the .018.This double serving gives me about a .105-.108 diameter which fits my nocks great without sanding them to fit.