When I made mine, I didn't make a circle skirt because I knew I needed more length and width for my straps than stated in the tutorial. I ended up making the skirt almost a full 360-degree circle skirt but not quite. I laid out the piece I wanted to cut to be the skirt, which was already folded the way it came off the bolt (I first measured from my waist to the length I wanted to make sure the fabric would be long enough once cut). The fabric was about 56" wide, so it would be long enough to make the skirt with half the width of the original fabric. I used that top fold to line up my waist hole, and ended up making the skirt in 2 pieces that were sewn up the side seams.
If that doesn't make sense, think of a rectangle, which I then "drew" a trapezoid-shape with the short end being centered at the top of the rectangle (the folded side). The short side of the trapezoid ended up being the waist, and the angled sides were the seams I sewed.