You are talking modern utikikilt style here, Most of those type kilts have a narrower apron than a a traditional style kilt. One has to decide whether you want the rank badges sewn on the right edge of the apron or a little further around to the right onto one of the pleats. Depending on the number of badges you are talking about, you could start about 3" from the bottom of the kilt and just go up in a vertical line from there. BobsYourUncle pics show where a line of badges would go on a traditionally made kilt