When I am making a dress or harness I use fusible interfacing. It is applied to the wrong side of the fabric and I also use two pieces of fabric for the top portion of the dress or the entire harness. Once you have two pieces of fabric and the interfacing it has plenty of structure. I use a medium weight non-woven interfacing. They come in a variety of weight as well as sew in or fusible. Can get confusing lol. Hope this helps
