It's a baisc rectangle skirt only this time I tried doing box pleats rather than gathering. The easier way to do this (I've found) is to start marking your skirt with however wide you want the please. If you want them to be 2 inches long (as I've done), then start marking two inches along the wrong side of the fabric.
Then, start folding. Fold so that the dot a 0" on the ruler is directly over the dot at 2", so you have about an inch going towards the right (pin in place). Do exactly the same on the other side going the opposite direction, so that the dot from 6" is directly over the dot at 4"
Now you should have a 2" long bit of fabric in front (kind of looking like a box) of your fabric strip. Now stitch it in place.
And very importantly IRON IT. That'll leave you with nice crisp edges. You don't have to iron it all the way down, just a few inches to make sure it has the sharp edge.
Now add a waistband and you're done!