I have some Weathered Ferguson strome (overkill for California) which would make two fantastic four-yard box pleated kilts. The pleating seems simple enough (even the tapering) and the overall construction would require only minimal adaptations to Barb's instruction book.

The one sticking point is sewing down the tapers where they butt up against each other. Do you sew one down to the fabric beneath and then sew the other next to it? or, do you sew the taper lines to each other from the front, and then sew the seam to the fabric beneath?