It's a nice discussion this - I guess why I'm here is to try and get the structure behind the repetition right. I have four sons, all in their teens, and want to be able to act as their tailor, effectively (that's if they want me to).

Greetings from Scotland guys - the trouser making series is fantastic, although I'm finding I have gaps as I try to follow along. Is it possible to get detail on how the measurement system works? I found the point I got lost was in the pattern drafting tutorial, when Rory switched (3rd video, around 13 and a half minutes in) to drafting the back parts of the trousers - sorry if I'm getting the terminology wrong! It took the front draft, and then used calculations to extend the shape to the size needed for the back draft. I followed most of it I think... but got confused at the part around extending the front fly into the back 'seat' area. I was wishing I had a reference that showed me what points Rory was mentioning. A brilliant tutorial though - as a hobbyist I'll be recommending this to friends.)