It took me a couple times to figure out how to do a pillow with a the right way. Well, I think it's the right way. I'm sure there is some tutorial out there that I haven't found, but since I figured it out, I have decided to do my own tutorial.
The trick was to sew the zipper on first. That helped a ton!
You will need:
1 uncovered pillow
zipper the length of your pillow
So, cut your fabric to size and pin the right side of the zipper to one of the right side of one piece of fabric.
Sew the zipper to the fabric along the edge. It is helpful to use a zipper foot, but I was sewing at a friend's house and she didn't have a zipper foot. It worked out fine because the zipper was thin.
After you sew the zipper to one piece of fabric, pin the other 1/2 of the zipper to the right side of the other piece of fabric.
Next, open up the fabric so the right sides are showing and fold the fabric so it hides the zipper like the picture below.
Now, pin and sew along the edge of the zipper.
Now you are ready to sew the pillow. Unzip the zipper a bit and sew the pillow right sides together.
Clip the corners and flip it right side out.
Nice pretty pillow all done!