Tutorial, part 8 - Sleeves

For the version WITH SLEEVES, sew the open sleeve (piece C) to the body assembly, right sides facing, matching edges and sleeve center with shoulder seam. (The sleeve is symmetrical, so either sleeve piece will do; there isn't a specific front or back.) 

Repeat for the other side.

Sew the sleeve and body side seam closed in one continuous stitch, right sides facing, matching edges and sleeve/body seam lines. 

Press seam allowances open. 

Repeat for the other side.

Fold the sleeve cuff (piece K) in half horizontally (the long way), right sides facing, and sew it closed. 

Press seam allowance open. 

Repeat for the other side.

Fold the sleeve cuff in half again, this time vertically (the short way), wrong sides facing, matching seam lines. 

OPTIONAL: Baste or sew the sleeve cuff across the seam allowances to ensure proper alignment with the sleeve. 

Stretch the sleeve cuff around the bottom of the sleeve and pin in place, open edges flush and matching seam lines. (Pinning excessively is unnecessary; quarterly or so should do nicely, perhaps with a couple more at the seam line.) 

Sew the sleeve cuff to the sleeve, right sides together. 

Fold the sleeve cuff downward. 

Repeat for the other side.

STANDARD ONESIE is finished! 

For FLY ONESIE, continue to next step.

For HEM VERSION, skip to step 10.