Design process
I'm making a pair of socks for a friend, and I wanted her to have a say in the design. The yarn had to be wool-free, which means Crystal Palace Panda Cotton or Panda Soy. The design came down to picking between various components.
Cuff
There are four types of cuff I like to make: plain hemmed, picot hemmed, rolled top, and ribbed top. The hemmed tops require a top-down sock, the others can go either way. All my BFL socks have a rolled top, my first rolled top was the Boudica socks from MimKnits which I loved until a moth got them. The sock recipient eliminated the hemmed tops which means I can do a toe-up sock. I prefer doing toe-up, but I do love the plain hemmed top.
Heel
There are two choices for the heel: the short row heel, and the heel flap. Both can be done toe-up or top-down. For this pair, she chose a heel flap with eye of partridge stitch for reinforcement. I've been using a toe-up heel flap pattern (PDF link), but following it can leave a small gap on the side at the top of the decreases that I'm working on eliminating.
Main pattern
The final design decision was left in my hands: some kind of cable pattern. There is such a thing as too much choice and my Barbara Walker book has at least eight that would work for what I have in mind. I like symmetry and mirrored patterns, and the yarn would benefit from some ribbing. I used the toe as my swatch, since I'm using true US1 needles (2.5mm) for the first time, and I need some extra stitches to account for the pulling-in from a cable pattern. I chose an off-centre Twin Waves cable. The book has instructions for a reversed version which I'll use on the other sock. The rest of the sock will be in 2x2 ribbing, so I'll knit a rolled top for the cuff. The cable is a tangled three-strand braid that contrasts with the straight ribbing, this is how it looks with two repeats complete:
Once I have a few inches of the foot done, there will be a fitting session to make sure the sock isn't too loose or too tight. I keep notes in a design notebook so a second sock, or a second pair, will be easy.