
How to do it
Ch 4, YO, insert hook in 4th ch from hook, YO, pull up a loop, YO pull through 1 loop on hook (ch made), (YO, pull through 2 loops) twice (first FDC made), *YO, insert hook into the ch made at the base of the stitch, YO, pull up a loop, YO pull through 1 loop on hook (ch made), (YO, pull through 2 loops) twice (second FDC made). Repeat from * until you have the desired number of stitches.
Visual Steps

Ch 4

Yarn over

Insert hook in fourth ch from hook

Yarn over

Pull up a loop

Yarn over

Pull though one loop on hook (ch made)

Yarn over

Pull through two loops

Yarn over

Pull through two loops (first FDC made)

Yarn over

Insert hook in the ch made at the base of the stitch

Yarn over

Pull up a loop

Yarn over

Pull through one loop (ch made)

Yarn over

Pull through two loops

Yarn over

Pull through 2 loops (2nd FDC made). Repeat from step 12