Use Steam-a-Seam Lite--not regular Steam-a-Seam.
I also like to use used dryer sheets for needle turn applique & invisible machine applique. Place your fabric face down on on the dryer sheet & sew around on the seam line. Cut a slit in the dryer sheet and turn piece right side out. Press & clip curves/points as needed to get it to lay flat. Lightweight non-woven interfacing would work also and I know a person that uses tulle the same way.