Here is my latest pillow and how I put it together. Supplies: A pillow top (15" x 15" for a 14"x14" pillow form) and two pieces (15" x 10" each) for the envelope back. A package of piping in a color to match or contrast. Sewing machine with zipper foot, thread, straight pins
Sew a hem on one 15" side of each backing piece. Lay the pillow top on your surface with the front facing you and place the two backing pieces onto of top, so that the hemmed edges over lap each other.
Open the package of piping and and unwrap it from the card
Start at the bottom middle of the top and lay the piping between the top and back layer with the piping roll toward the center and edge along the edges of the material. Pin all the layers in place with straight pins.
When you get to the corners, don't even try to make them square, just round the corner and use extra straight pins to hold it in place.
Continue all the way around the pillow. Over lap the piping when you get back to your starting place.
Put your zipper foot on your machine.
Starting where you over lapped the two ends, sew right along the edge of the piping, all the way around the pillow. Stay as close to the piping roll as possible (I have been doing this for years and I have yet to get it perfect).
Check to make sure you don't have any gaps, then trim around the corners.
Reach in between the two overlapping back pieces and turn the pillow right side out.
There it is, done!
To stuff the pillow form into the pillow, reach in through the top half of the bottom layer and start stuffing the form in. Then pull the bottom half down and cover the form with the bottom of the pillow cover.
Here is what it looks like with the pillow form in it. This method can be done with any size pillow. Good luck and enjoy!