I was taught one method of producing these at school by Mr Woods, yes that was his name my highschool woodwork teacher. He had come into teaching during the teacher shortage created by the Vietnam war, he was a towering 6'4" but a tradesman and had been a production turner at some stage.
Years on David Laird from the OTGA taught Sue another method and its this I am using to produce a column for the 3 teir stand. This involves the same layout method in the link above but using Micro-planes to form the Barley twist. This is a 4 start twist.