Does the designer suppose you know what to do with this loop you are now having on your hook? Does it obvious how to stuff, fasten off and so on? – Not always.
3. Thread the yarn tail you have left. And pull it under each front loop of your final 12 stitches. Insert your needle from outside towards the center beginning from the first stitch. Pull the yarn a little after each one or two stitches. If while doing it you discover even a little of empty space inside add more stuffing and then continue.
5. Pierce through the crocheted detail to any point (the further the better). Pull hard but carefully enough not to deform the detail. Don’t stop pulling the yarn tail cut it as close to the crocheted surface as possible. That’s all. Your upper part is as nice as the bottom one!