This uses just one stitch, Grecian Plait Stitch, pg 131.  It was a very interesting stitch to do.  You switch needle sizes each row.  You knit round with a needle 4 sizes larger than normal (6mm), then use the regular size needle for the yarn (4mm) to lift one stitch up and around the other as you knit it.  It was pretty slow going for quite a while before I developed the knack.  In the variation, you stagger the stitches that are pulled over as they are knit.

This is a two stitch repeat, so I decided it was easiest to do a double decrease.  I did a slip one, knit two together, psso for the decreasing.  I used 6 points of decrease and decreased every second row on top of the last decrease.