Barb Tewksbury, of The Art Of Kiltmaking fame (and whose advice I followed to sign up to this forum) offers a free PDF supplement to her book, "that provides additional instructions for making a traditional box pleated kilt." On page 7 of this document is a diagram with 4 different pleating styles, as well as a lot of details regarding the evolution of knife pleated kilts in history.

Her website will be found at https://www.theartofkiltmaking.com/l...iltmaking.html , the link to this PDF is at the bottom right. If you must just get the document right away, it can be found in https://www.theartofkiltmaking.com/files/126367176.pdf though I earnestly encourage anyone interested in kilts to visit the website itself, more info than I would imagine is there.