For our Deluxe Slocks we use 8ply Tarndie yarn -
Cast on given stitches(tightly)
Knit 4 rounds, turn heel,
knit foot as given but add half of the foot length measurement the pattern asks for,
Shape toe and felt.
There is no need for the normal finishing, like sewing in ends, as the felting process will secure all joins and yarn ends.
Felt to a snug fit and stretch onto foot whilst still damp, the Slocks will then take on the shape of the individual foot. This stretching will need to be repeated after each wash.