I made two pillow covers this morning. The first one, proved to be too small (I didn't measure my pillow well enough), so I made that one into a smaller pillow cover for a smaller pillow. The second attempt seems a little too big, but I blame the tutorial. Aside from that, and my slightly crooked line on one side, it looks pretty good. I even remembered to back stitch.
Check out the smaller of the two pillows: