I've been going through Cat Bordhi's sock book, New Pathways for Sock Knitters. She has invented a bunch of new ways to knit socks; the innovation mainly lies in the way the arch expansion is created. On a "regular" sock, you knit the heel flap and turn the heel, and then you pick up stitches alongside the heel flap to make a gusset, which you then reduce as you knit around the sock. This makes the sock fit over the "fat" part of your foot when you pull it on. (If you wrap a tape measure from your heel over your ankle and back to your heel, you'll see that this part of your foot is quite a bit bigger than the circumference of your foot alone, or your ankle alone. For me, it's 150% of my foot circumference.)
Cat Bordhi has invented eight (count 'em!) new ways to deal with this sock architecture problem. I have been trying them, and I'm on number 2, Cedar Architecture. Cedar Architecture is pretty simple: you just increase gradually anywhere you want to around the sock, until you have enough stitches to reach around the instep plus heel! Then you do a short-row heel turn on the bottom of the sock. This special heel turn uses up the extra stitches that you added when you increased, so that by the time you start knitting the foot, you're back to the right number of stitches around. It's sort of mysterious to me still.
Anyway, this new form of arch expansion is liberating, design-wise, because the design of the ankle can continue all the way down to the bottom of the foot, without being interrupted by any heel flap. In this pattern, called Slipstitch Rings, the last pattern ring is right before the heel turn. Cool!
I used a multicolored sock yarn that was on sale at KnitPicks, as well as some left-over yarn for the rings.