I bought a better iron than I had previously. I used a Rowenta iron. I didn't use an interfacing because I lined it with a pink acetate lining instead. I usually line my dresses to have a more expensive look. Hope this helps!
The coat material was a loose woven that was falling apart as you cut it, so I used an iron on fusible interfacing to keep it together. I lined it with a pink acetate lining.