Use the smallest needles you can. I use UK size 2.
Yarn should be 4-ply, very fine (Double knitting/regular wool is OK, if you knit tightly)

Front
Cast on 20 stitches
Rib (K1, P1) for 3 rows
Beginning with a purl row work in stocking stitch (K1 row, P1 row) until work measures 3.5 cms or between 1 and 1.5 inches.
This can vary and you can make it longer, or shorter for a cropped look to it’s up to you

Shaping the armhole
Staring with a knit row, cast off 2 stitches at the beginning of the next 2 rows leaving 16 stitches
Next row: Decrease (or Knit 2 together) in first and last stitch (14 st)
Starting with a P row, work 3 rows straight

Shaping the neck
(Right side first)
Knit 3, Knit 2 tog.
Turn and P these 4 stitches
Knit 2, Knit 2 tog
Turn and P 3
Knit 1, Knit 2 tog
Turn cast off remaining 2 stitches
(Left side)
Rejoin yarn and cast off 4 stitches, K 2 tog, K to end.
P 1 row
Carry on decreasing 1 st at neck edge in the same way as for right side, until 2 stitches left.
Cast off.

Right Back
Cast on 12 stitches
Rib (K1, P1) for 3 rows
Staring with a P row, continue in stocking stitch, as for front.
Beginning with a purl row work in stocking stitch (K1 row, P1 row) until work measures 3.5 cms or 1-1.5 inches.

Shaping the armhole
Staring with a K row cast off 2 st at beg of row, K to end (10 st)
P 1 row
K 2 tog, K to end (9st)
K 6 rows

Shape Back neck and shoulder
Staring with a P row cast off 5, P to end
K3, k 2 tog.
P 1 row
K2, k 2 tog
Cast off Purlwise

Left Back
Cast on 12 stitches
Rib (K1, P1) for 3 rows
Staring with a P row, continue in stocking stitch, as for front.
Beginning with a purl row work in stocking stitch (K1 row, P1 row) until work measures 3.5 cms or 1-1.5 inches.

Shaping the armhole
Beginning with a p row cast off 2 st ,P to end
K to last 2 stitches, k 2 tog
Work straight for 7 rows

Shape Back neck and shoulder
Beginning with a k row. Cast off 5 stitches, k to end
P 1 row
K 2 tog, k2
P 1 row
K 2 tog, k1
Cast off

Sleeve (make 2) - optional
Cast on 14 stitches
Rib (k1, p1) for 2 rows
Work straight in Stocking stitch (k1 row, p 1 row) Until the work measures approx 4 cms, from the dolls wrist to underarm.

Shaping the shoulder
Cast off 2 stitches and the beginning of the next 2 rows (10 st)
Next row: Decrease 1 at the beginning and end of this row (8 st)
Beginning with a P row work 3 rows
Next row: Decrease 1 at the beginning and end of this row (6st)
P 1 row
Decrease 1 at the beginning and end of this row (4 st)
Cast off 4 stitches

Roll collar - optional
Cast on 30 st
Work in k1, p1 rib for 10-20* rows without shaping
*If you’d like a big chunky roll collar work more rows
Less for a turtle neck, which doesn’t fold over.
Cast off

Finishing and sewing up
Sew in and secure yarn rejoined at front neck edge.
Sew right and left back to the front along the side seams
If you have sleeves sew them along the edge from the wrist to the armhole shaping.
Take yarn at the top of the sleeve and sew it through the front and back sections, continue to sew the sleeve in around the armhole, for both sleeves.
Sew shoulder seams and tie off any other strands of yarn securely.
Attach the collar to the neck edge.
To close the back, sew snaps to sweater backs, so that backs overlap slightly. Position one snap at neck edge and one snap just above bottom ribbing.