Materials: DK weight yarn, 1 or 2 50 gm balls.

Materials note - if you wish to make the child's size socks from 1 ball of DK yarn, use no more than 5 pattern repeats in the leg. Personally, I recommend getting 2 balls of yarn, using 8 pattern repeats in the leg, and using the leftovers to make the toddler size! (Red socks pictured show 5 pattern repeats, green socks show 6, purple shows 8.)

Needles: 2 #5 circular needles, or size needed to obtain gauge.

(If you wish to use DPNs, I recommend using 5)

Gauge - 5 to 6 stitches per inch.

The instep stitches stay on one needle throughout, and the heel stitches on the other.

Cast on 40 stitches loosely. Move half the stitches to the second needle. Join, being careful not to twist the cast-on round. Work 6 rounds of K3, p2 ribbing. Then work one round of *K1, p4; rep from * around.

Pattern rounds:
Rnd 1: *K4, p1; rep from * around.
Rnd 2: *K3, p2; rep from * around.
Rnd 3: *K2, p3; rep from * around.
Rnd 4: *K1, p4; rep from * around.

Repeat the 4 pattern rounds until your leg is long enough. End on a K1, p4 row. Note repeated - if you wish to make the child's size socks from 1 ball of DK yarn, use no more than 5 pattern repeats in the leg. Personally, I recommend getting 2 balls of yarn, using 8 pattern repeats in the leg, and using the leftovers to make the toddler size!

When you are satisfied with the length of the leg, begin your heel flap on the 20 stitches on the next needle while the other waits.

Row 1:
Sl 1 purlwise, * K1, Sl 1 knitwise; repeat from * until last stitch, K1.
Row 2:
Sl 1 purlwise, p18, K1

Repeat above 2 rows 10 times, for a total of 20 rows.

Or if you prefer an eye of partridge style heel flap:
Row 1:
Sl 1 purlwise, * K1, Sl 1 knitwise; repeat from * until last stitch, K1.
Row 2:
Sl 1 purlwise, p18, K1
Row 3:
Sl 2 purlwise, * K1, Sl 1 knitwise; repeat from * until last 2 stitches, K2.
Row 4:
Sl 1 purlwise, p18, K1

Repeat the above four rounds 5 times, for a total of 20 rows

Turning the heel:
Row 1: Sl 1, K11, ssk, k1, turn
Row 2: Sl1, p5, p2tog, p1, turn
Row 3: Sl1, k6, ssk, k1, turn
Row 4: Sl1, p7, p2tog, p1, turn
Row 5: Sl1, k8, ssk, k1, turn
Row 6: Sl1, p9, p2tog, p1, turn
Row 7: Sl1, k10, ssk, turn
Row 8: Sl1, p10, p2tog, turn
Row 9: K12 (place center marker halfway across if you use one)

Picking up Gusset stitches:

With the same needle that you've just K12 with, pick up 11 stitches along the side of the heel flap. Pick up one more stitch in the intersection where the heel flap meets the instep stitches, to prevent a hole.

Switch to the instep needle, start the pattern rows again, with a K4p1 row. The instep needle will simply be following the pattern rows all down the foot.

With the empty end of the heel stitches needle, pick up one stitch where the heel flap meets the instep. Then pick up 10 stitches along that side of the heel flap. .

(Yes, at this point you will have many stitches on that needle. It is a bit tricky at first, but gets easier quickly)

Gusset:

Knit across the heel stitches and the other gusset stitches to the last stitch, which you'd picked up in the intersection. Knit it twisted.

Knit next row of pattern on the instep needles.

Heel needle, knit the first stitch twisted, knit to center.

Your gusset rounds now start from here.
Round 1 - knit to last 3 stitches of heel needle, K2tog, K1. Instep needle, continue pattern. Heel needle, K1, SSK, knit to center/marker.
Round 2 - Knit to end of heel needle, knit in pattern across instep needle, knit to center/marker.
Continue this until the heel needle has 20 stitches on it.

Foot:

For the foot, knit in pattern on the instep needles and in stockinette on the heel needles until the foot is two inches short of the end of the toes.

For my available child model, I went 10 pattern repeats PAST the cuff. (So if you want to try to finish a pair out of 1 ball, 15 pattern repeats total. The version I liked best from 2 balls was 18 pattern repeats total.)

End on a K1, p4 row.

Toe:

The pattern repeats end here, you will knit all stitches. Again, the round 'starts' at the middle of the heel needle, use a marker if need be.

Round 1 - knit to last 3 stitches of heel needle, K2tog, K1. Instep needle, K1, SSK, knit to last 3 stitches, K2tog, K1. Heel needle, K1, SSK, knit to center/marker.

Round 2 - K all sts.

Continue this until there are 8 stitches left on each needle. Knit one round. Knit to the end of the heel needle. Slip the 4 sts closest to the needle ends over their adjacent neighbors. Use the kitchener stitch to join the remaining 6 instep stitches to the remaining 6 heel stitches.