Here's the pattern:
Easy Slip Stitch Slipper Sock
Double knitting yarn in main colour
Contrast colour. Boucle yarn works well for contrast, but any double knitting yarn in a contrasting colour will be fine.
5 mm needles.
Note: To slip stitches, transfer stitch from left hand needle to right hand without knitting it.
With main colour, cast on 34 stitches. Knit two rows. Then begin the pattern:
Row 1: With contrast yarn, knit
Row 2: With contrast yarn, knit
Row 3: With main colour, knit 2, *slip 2, knit 2 to the end
Row 4: With main colour, purl 2, * slip 2, purl 2 to the end.
Repeat these 4 rows until the the work measures just less than desired foot length. Knit two rows in main colour and cast off.
There are two ways of doing the cuff, in the round or flat.
Cuff in the round
Fold the work in half lengthwise. Sew the cast on edges together to make the heel. Sew the cast off edges together and then sew along the top of the oblong to make the top of the sock, leaving opening.
Using main colour and double pointed needles, size 5 mm, pick up 32 stitches around the opening and work knit 2, purl 2 rib for desired length Cast off in rib. Looks better if you make it long enough for the cuff to turn over, but this isn't essential.
Mark where opening of sock will be. Using 5 mm needles and main colour, pick up 16 stitches from cast on edge to marker. Work knit 2, purl 2 rib for desired length. Cast off. Work the other side the same. Then sew cast on edge together, continuing to top of cuff. Sew cast off edge and continue sewing along the top of the sock and to the end of the cuff.
Since the brief was a 'challenge', I thought I might make another pair that is more difficult. Perhaps using a technique that I'm not familiar with. Watch this space!