I find that a stabilizer is needed, to avoid puckering in applique. As QuiltnNan said - you can use fusible. I actually used a piece of paper last time - layer paper, quilt, applique and stitched through all 3. Worked great, and then I tore it off, like paper piecing.
Next train car? Am I missing something? Sounds like your friends are making disappearing 9-patches
http://www.popularpatchwork.com/site...structions.pdf