Objective: Combine your intermediate MC6650 skills into a complete, saleable lined zippered pouch, following a logical construction order with built-in quality checks.
A real-world product is less about new stitches and more about sequencing skills you already have so the result looks professional and sells. A lined zippered pouch is the ideal first saleable item: it uses straight stitching, a zipper installation, backstitching at stress points, pressing, and clean corners. The MC6650 makes this easier than a basic machine because its automatic thread cutter, adjustable speed slider, and needle up/down button give you control around the zipper pull and corners. The construction logic is: cut your pieces, attach the zipper between outer fabric and lining (sandwich method), topstitch to keep the lining from catching, then sew the outer-to-outer and lining-to-lining while leaving a turning gap in the lining, clip corners, turn right side out, press, and edgestitch the gap closed. Set the MC6650 to a 2.5mm straight stitch for seams and use the zipper foot for anything near the teeth. Lower the speed slider to about half when sewing past the zipper pull so you can nudge it out of the way with the needle down. Buyers judge handmade items on three visible things: even topstitching beside the zipper, square corners, and no puckers. These are your quality checkpoints and should guide every pressing and stitching decision.
Example: Make a 9" x 7" pouch. Cut two outer and two lining rectangles at 9" x 7", and one 9" zipper. Lay outer fabric right-side-up, place the zipper face-down along the top edge, then lining right-side-down on top; pin. With the zipper foot, straight-stitch at 3/8". Flip both fabrics away from the zipper, press, and topstitch 1/8" from the fold. Repeat for the other side. Open the zipper halfway (critical so you can turn it later). Match outer-to-outer and lining-to-lining, leaving a 3" gap in the lining bottom. Sew around at 3/8", backstitching at the zipper ends. Clip the four corners diagonally. Turn through the gap, push corners out with a blunt tool, press flat, and edgestitch the gap closed.
Try it: Sew one complete lined zippered pouch on your MC6650 using the sandwich method above. Before turning it right side out, pause and verify your three quality checkpoints on the inside: topstitching runs evenly beside the zipper, seam allowances are a consistent 3/8", and the zipper is open halfway. Finish, press, and write down one step that caused trouble so you can refine it on your next unit.