To knit house slippers, cast approximately 35 to 40 stitches on the knitting needles, and knit using garter or rib stitching until the piece measures around 6 to 10 inches in length. Fold the piece in half, and sew the rectangle's perimeter, leaving an opening to slide the foot in.
It is best to use worsted, medium-weight yarn with a pair of U.S. 8- or 5-millimeter knitting needles for the knitted slippers. With the yarn, cast on the required number of stitches on the needle. Using the garter stitch, knit each row until the piece is around 4 inches in length.
Then, continue the garter stitch so that the pattern measures 6 to 10 inches. For a rib stitch, alternate between knitting and purling for each stitch, and repeat this process in every row until the required length is achieved. The exact length of the piece depends on the length of the foot. Ideally, the pattern's length should be around 1 inch less than the length of the foot.
Cast the stitches off the needle and snip the yarn, leaving a tail that is 6 inches long. Weave the tail yarns using a blunt needle.
After folding the piece in half, sew the short sides together. Sew the longer side until you reach the halfway point. This leaves an opening in the slipper. Crochet one row of single crochet stitches around the slipper's opening to secure it. Finally, weave any yarn tails. Knit the other slipper in a similar manner.