Lessons learned from my first pair of kneesocks --
- A leg that is too long is better than a leg that is too short. If the leg is too long, one can simply fold over a bit of the cuff at the top. Too short, and the sock bags, sags, and eventually slips down to the ankle.
- A nice tightly ribbed cuff at the top is essential. It helps to hold up the sock and it provides the necessary flexibility for the leg length.
- The shaping from knee to ankle should go from medium to large, back to medium, then down to small at the ankle. If it starts large and gets progressively smaller, same problem as #1 -- saggy, baggy, slidey sock.
I learned all these things in the usual way -- by screwing up. The pattern I selected ("Stockings with Clocks" from Nancy Bush's "Folk Socks"), while lovely, had some issues in the shaping department. The charmingly patterned cuff had zero elasticity.
And the shaping went from large to medium to small. And then I made the leg too short, which really didn't help. The end result was beautiful kneesocks that simply would not stay up. Sooooo.. . . here's the quick fix--
I picked up a bunch of stitches at the top (slightly fewer than I had cast on). Then I knit four inches of K2P2 ribbing. The ribbing can fold down over itself for a two-inch cuff or fold all the way down over the original decorative top. End result: lovely kneesocks that STAY UP!