Suitable for knitters with sock knitting experience, this is a fascinating and fun way to knit two socks at the same time - one inside the other!
The pattern provides a training version as well as actual sock-sized versions. I suggest you start with the training version - it's a quick knit, and using thicker yarn and needles allows you to get confident with the technique.
Several versions of this technique have been published in the past few years. This pattern provides two key improvements: there are multiple sizes, and I've engineered it so that the socks exactly match the result if you were to work in the normal manner.
Although the pictures are shown with dpns, the pattern is written for any needle type: dpns, magic loop or two circulars. Top-down.