I press my fabric first and make certain any wrinkles are out. Then I do as Murphy 224 does, lay the interfacing glue side up and lay the fabric over the top. I will press to warm the glue up thru the fabric and then flip and press from the back. Parchment paper helps but does make me want to iron and that's not the thing to do. Make certain that nothing it wet with starch or steam. Unless the fusible works that way.