I knew when I talked about trimming off the corners in my last post I wasn't being very clear. I wanted to post a drawing yesterday, but didn't get around to it. Sure enough someone asked for a bit more insight into what I meant.
So I give you this super quick and not very good illustration to hopefully help it make more sense.
After you cut out your pieces, places them right-sides together and trim off a bit of each corner (called a bow) as shown starting from about 1/2 in. in from the corner tapering off to nothing at 2 in. (as shown).
When you sew your seams follow this new edge. The bow makes up for the dip (like rabbit ears) that you would see in the filled pillow if cut straight across (thank you upholster.com for that explanation. I was having trouble finding the words). When you turn your pillow and insert the pillow form you'll have a truer rectangle shape.
Hope this helps. For full instructions with photos on upholster.com click here. They also have instructions for installing zippers. I don't think you want me to try and explain that one : )
Happy Friday! I'm hoping to finish my other pillows this weekend and will post next week.