Thanks for this! It was really nicely explained and to the point. I was just making myself a waistcoat with a collar these past few days, and managed to figure out the favouring (though I didn't know the word for it) and next time I'll know how to account for the turn of cloth too! :)
Turn of cloth isn't talked about that much but is so important, especially to make lapels and collars lie flat and smooth. This tip I discovered while experimenting, and it works like a charm.