This week I improvised, quite successfully, lengthened sleeves for Ari's Baby Surprise Jacket, (despite negative design criticism, I might add!). The sleeves were about 5", which now looks silly on him, although the jacket is still long enough. So, I picked up 40 sts along the sleeve edges on #6 dps. Make sure to pick up enough around the seam line -- but not too many or it will flare out at that point. I knit for 1" and then decreased on either side of the underarm center. Decrease again at just under 7" and 8", then again at 8.75", 9.5" and 10.25". Now there are 28 sts. on the needles. Bind off very loosely at 11". I did this to make a cuff with the darker colorway covering the white and resulting in a 9" sleeve. Ari seems to grow up rather than out so I wanted to make the sleeves long enough.
As for the mittens, I improvised, using the sleeve edge circumference as a guide. I cast on 28 sts, ribbed in k1p1 for 2". I like nice long mitten cuffs to keep the snow out in case snow suit jackets don't have nice, tight knitted cuffs. Using a twisted st pattern for a thicker, warmer fabric, I began the thumb gusset 1 row after the rib. I made the thumb gusset 9 sts and will start to decrease for the top at about 3.25" from the cuff. I was very pleased when I checked in Ann Budd's The Knitter's Handy Book of Patterns that my instincts had been right on the money for my gauge of 5.5 in the twisted st.