It's something I learned here on the board.
You take the applique pieces with the fusible already on them (the part I skipped before - d'oh!) and glue them in place with a THIN layer of elmer's school glue. (It HAS to be the washable school glue!) Iron with NO steam to dry the glue, then sew the pieces on. The glue holds them in place so you can glue them without chasing them around the quilt, and when you wash the quilt, the glue comes out!