If you want to use the ties you've got and you're a pencil-neck like me, even a full Windsor won't do the trick. However, once you have the front (wide part) of the tie properly located at the top of the belt buckle, pull the part tied around your neck until the narrow part of the tie is also of proper length. Pinch the excess in the neck, cut it off, and sew the ends together. Voila! a kilt-length tie custom made for you.