Ch for desired length, thread over twice, insert in 5th st from hook, * work off two loops, thread over, skip 2 sts, insert in next st and work off all loops on needle 2 at a time, ch 2, d c in center of stitch to complete cross. Thread over twice, insert in next st and repeat from *. This is sometimes called K stitch.
Source: Revised Beginner's Manual, Star Book No. 62