I consider my "Flatfold Knitting Technique" to be a progession on the technique: tubular double knitting, developed by the late Beverly Royce.
In the work above, the knit work was cast on closed and thrummed with silk while being knit in the round on a pair of straight needles. It is primarily knit inside out for the convenience of working "knit 1 back stitch, slip 1 front stitch" in one motion rather than moving the working yarn to the forward and back positions. This lends itself well to thrumming.
As you can see, after working the tube, I began knitting back and forth to create a slit opening at the chest and then proceeded to use bind off decreases until half of the total number of stitches were on one needle. These will be folded in half and kitchenered to make the hood of the silk thrummed baby swaddle pod.
In the second photo is the ECO Sock in progress. Half of the total number of sts was cast on and worked back and forth to make the heel. Increases are worked on the other side of the Flatfold and needle until the total number of sts have been increased. The foot rows will then be worked in tubular double knit on a pair of straight needles.