I took the pattern from the Fiddlehead Mittens and modified it so that the count is 64, by adding another vertical line to the end of the pattern. The original pattern repeats itself after 30 stitches, so by adding just 2 columns, I got the desired 64 stitches since the pattern repeats twice around the sock.

I also made minor alterations to the original pattern because I really hate knitting long rows of same color with the same yarn in the middle of the pattern, it makes it difficult to keep the tension of the second yarn regular. I added stitches of the CC here and there but the overall look is the same.

Main color, MC = lime green
Contrasting color, CC = dark grey

The cuff:

1. Rib cast on with needles no. 4
2. Knit 15 rows of rib with MC
3. Knit 5 rows of stockinette with MC
4. Knit 1 row with CC
5. Knit 1 MC, knit 1 CC, repeat for 5 rows
6. Begin pattern, see picture.
7. Change needles to no. 3.5 in the middle of the pattern, this is to keep the count as is, but to make the cuff a bit narrower towards the anckle.
8. After finishing the pattern: Knit 1 MC, knit 1 CC, repeat for 5 rows.
9. Knit 1 row of CC.
10. Knit 2 rows of MC.

The heel:
Take 2 needles and check that the part where you have changed rows is the part which will be on the inside of the foot, it will look nicer if the color changes and whatnot doesn’t show on the outside. Now knit 1 MC, knit 1 CC, repeat for as long as you need to make the heel flap long enough.

Remember! Always knit both of the yarns together on the last stitch! This will prevent any holes or other issues with the yarns which you might encounter if the yarns were just twisted together at the sides.

Knitting vertical stripes is quite easy, but it’s too easy to tighten the yarns a bit too much. Although the heel is the best place to do that, since it’s actually better to make it a bit too tight, it will last longer.

I knitted 22 rows of vertical stripes before beginning the short rows. Also, I planned the short rows so that I turned the flap when I hit the 5th column of CC, counting from the edge of the flap. I stopped knitting the vertical stripes when I had knitted all the short rows.

The foot:

1. Pick up the stitches from the heel flap and knit the gussets with MC however you wish.
2. Keep trying it on, so you know when to stop gusseting. It took me 10 rows to get the count down to the desired 64 stitches but I decreased on every row, not on every other row as many sock patterns suggest.
3. After the gussets, knit 1 row of CC.
4. Change needles from size 3.5 to 4. This will help you to keep the gauge as is compared to the one-colored parts. You don’t necessarily have to do this, if you have the habit of overcompensating while knitting patterns. I do the opposite, especially with vertical stripes.
5. Knit 1 MC, knit 1 CC, repeat for 5 rows. Remember to start your rows from the same stitch every time, this is to ensure the pattern on the foot is leveled with the pattern in the cuff.

Now’s the tricky part:

1. Knit pattern from row 1 to row 14. You should finish with a half a pattern.
2. Knit 1 MC, knit 1 CC, repeat for 5 rows. Check that the vertical stripes start from the same stitch as in the beginning of the pattern.
3. Knit 1 row of CC.
4. Change needles from 4 to 3.5, you can do this while you knit the next row with MC.
5. Knit with MC as many rows as you need to get the sock to almost cover your pinky toe. This took me 8 rows.

Finishing the sock:

1. Decrease on every other row, once on every needle, until you have 10 stitches on each needle. This means you have 4 decreases per row when you’re making them and 0 decreases on every other row. It’s fine if you want to make 2 decreases on every row, it’s a matter of taste. This phase took me 8 rows.
2. Decrease on every row, once on every needle, until you have 2 stitches left on each needle. This took me also 8 rows.
3. Take the yarn, cut it and pull it through the stitches.
4. Finish the ends.

Pictures up finally!