I improvised this design after looking up all the tiny sweater patterns here on ravelry and having my head explode in confusion.
All in magic loop, one set of needles and one stitch holder.

CO 28
K1P1 for 5 rows
knit until the underarms
BO one stitch, knit 12, BO place the remaining 14 stitches on a holder
Work back and forth until you cleared the arms.
place those stitch on the long needle cable
Break the yarn
Pick up the stitches on the stitch holder.

BO 1 knit the 13 stitches BO 1,
knit back and forth for the same amount of rows as the other side
join in the round again and knit 2 rows
start decreasing:
SSk, knit 8, K2TOG, SSK, knit8, K2TOG
ssk, knit 6, K2TOG,ssk, knit 6, K2TOG
k1, P1 the rest of the collar
BO.

sleeves

pick up 14 stitches around the sleeve opening and knit in the round
finish with a k1p1 border for 4 rows, BO
repeat on the other side
weave in loose ends