Instructions
To create a rib effect: - This stitch works well with any of the treble stitches.

Rather than picking up the loops from the top of the row below simple work the hook in front or behind the whole stitch.
Simply alternate how you pick up the stitches.
For the first stitch pick up the stitch from behind.
The second stitch pick up from the front.
The third stitch pick up from behind and so on creating the rib effect.
When you turn your work simply pick up the stitch to match the previous one below.