I always iron my jersey first, seems weird I know, but it does help. Fold the 1/2 yard piece in half lengthwise, so you end up with a 9" x45" rectangular strip. Sew/serge the edges shut leaving a gap to turn it right side out. Flip it out, iron it and sew the opening shut. Now you have a lovely long rectangle. Thrilling, I know.
Then take the fabric and pleat it upwards one inch so your ruler only shows 2 inches. I find this the easiest way to pleat since I haven't tried making a pleating board yet.
Keep your pleats folded nice and even, which can be difficult and don't worry if it looks bad, (it will!), all will be ok once you unpin it. I sew a line of stitching on either side of the center row, totally optional.