Mine are both 54" X 54", with a 1" fringe. The store-boght one has a corner that's been pleated and stitched, the one that I made does not.
Having worn them both, I really can't say that the stitched-in pleat at one corner is important to me, and I wanted to be able to fold it flat, as an Irish brat (or a day plaid), so no sewing's involved.
I marked 1" in on the blade of a pair of shears, and made a series of 1" deep cuts along an edge; mybe 4" - 6" or so. Then I spent a loong time on the couch with a sailmakers needle tatting out the threads. I've been quite happy with the result; wore it yesterday, and will again tonight (I'm wearing it in my avatar).