Step 1: Cast on stitches for i-cord (normally 3 or 4), and knit all stitches.
Step 2: Now slide stitches from left end of DPN to the right end. Don't turn the needle!
Step 3: You will now knit your stitches from right to left as normal. The working yarn will pass behind the stitches in order to knit the first stitch. Give the yarn a tug before the first stitch to ensure even stitches. Then finish the row.
Step 4: Repeat steps 2 and 3 until your i-cord reaches the desired length. Cast off as normal.