I recovered my pillows on my couch and I LOVED how they turned out. So much in fact, I thought I would share the love and show you how I made it. And because I know you will ask, the funky flower pattern fabric is from Joann Fabrics.
I used an old pillow form to get measurements. I flipped the form inside out and measured diagonally from one corner to another then multiplied that number by 3. That number gives you the length you need for your ruffle. Decide what width you want it to be. I was making a large pillow so I did mine at 6 inches. Gather both sides length wise of the ruffle.
I forgot to take pictures for the next part, but it is really easy. I made an envelope back by cutting 2 rectangles from the salvaged edge (that way I didn't need to hem the bottom. Genius I know:) Make sure they have at least 4 inches over lap so the pillow won't show when put into cover.
With RST sew the pillow front to the pillow back. Reinforce the edges where the flaps meet. This prevents tearing when taking pillow in and out. Here they are on the futon. The polka dot pillows are from Ikea. I LOVE it! It dresses things up a bit and makes the couch fashionably comfortable.