You need the double twisting method on any cable longer than a couple of
metres or so.

This is how the noise boys do it. They wrap a lot of cables, some of them
100's of metres of multicore which is a damn sight stiffer than B&W mains
cable.

http://www.youtube.com/watch?v=yqbYy...eature=related

You will notice about half way through, this method corrects a spiral that
was in the line, letting it go on to the spool in his hand correctly.

Steve