Hmm, Just found this dress which is by Maggy London the same designer as the pattern I'm using and is very similar to the pattern I'm using, the midriff part is just thinner.
But how did they get the gathers so small!! Mine are kinda chunky :(
My first method, used on the neckline, was to sew two rows of stitching, both inside the 1.5cm seam allowance and then pull the top threads to create the gathers. But on the midriff I sewed the lines of stitching either side of the seam line (and then pulled out the threads after sewing the seams) and this produced a better result but still not as tiny as these gathers ... poo.