I was so happy with the sleeve poof. It turned out just as I had hoped it would. I love the fit and made a few easy mods to make it smaller. My modifications:

To make an XS:

Knit with a much smaller gauge. (DK weight instead of Aran weight.)
Stopped yoke at row 37.
At raglan shaping I repeated rows 3 and 4 six times only.
I had 153 sts for body and 46 sts for each sleeve.

It was still too big so I put it in a hot water wash and hot dryer. It shrunk about an inch in width and length which made it a better fit. The ball band will tell you not to do this of course, but it’s cotton and linen and those two can go in the washing machine and dryer. Normally they would not shrink, but this was a planned shrink with HOT!

For sleeve poof: (These are knitted top down in the round.)

To taper the sleeve I made two mirrored decreases before the elbows: 42 sts.
At elbow, kfb each stitch across row: 84 sts.
Knit to desired length of poof.
To finish:
Row 1: K2tog across row: 42 sts.
Row 2: Purl
Row 3: K1, K2tog, K to 3 sts before M, K2tog, K1: 40 sts.
Row 4: Purl
Row 5: Bind off knitwise.

Wow! In these pictures I was really surprised to see a dye lot change in the yoke. I thought I always checked dye lots but in this case I guess I didn’t. It’s weird because you can’t see the change with the naked eye, but a camera will magnify anything done wrong in a knit, right? No mercy.