I finally got around to finishing the pillows that I started here. It's amazing what you can get done when you are procrastinating and putting off actual work.
I left off with the stenciled from square of the pillow. The next step is to cut out two more rectangles of fabric. The width of the rectangles should be the same as the pillow but the length should be about four inches shorter. This will create an overlapping opening that you can stuff the pillow into. Finish the top edge of the two rectangles by folding the edge over 1/4 inch, pressing it, folding down another 1/4 inch and sewing it in place with a straight stitch.
Now lay your stenciled square down in front of your, stenciled side facing up. Line the bottom of one of the rectangle flaps up with the bottom edge of the square. The finished hemmed edge will be on the top and you want the "good" side of the fabric facing down, against the stenciled square. Then lay the second rectangle on the the top of the square, so it overlaps the first rectangle.
Now pin all around the perimeter of the square. Sew a straight stitch around the square. This is why I love this kind of pillow. Not only can you remove the cover and wash it, but you also don't have a weird looking seam that needs to be sewn after you turn the pillow right side out. All of these seams will look clean. After you finish sewing around the edges, use your sewing scissors to clip off the points of fabric on the corners. Make sure you don't get too close to the stitching though. This will help the corners turn inside out.
After this, just turn the pillows covers right side out and stuff the pillows in. Do this carefully. I ripped one of my stitches when I tried to stuff one of the cases. So I ended up going back to the sewing machine and sewing back and forth over the little sections where the flaps overlapped. This reinforced it much better. Here are some pictures of the finished products: