After seeing sweater pillows by Martha Stewart and on etsy.com for $50, I decided to make my own. My version is the one on top. Here's a quick demo of what I did.
First, measure the pillow you want to cover. I recommend using an extra large sweater.
Next, remove the sleeves and neckline using scissors.
This is what the sweater will look like minus sleeves. Now I cut the same amount from the front and back of the sweater to make a square shape.
Use yarn in a whip-stitch or blanket stitch pattern to join seams. You can use yarn of the same or contrasting color. I selected a cream color.
I made my pillow in an envelope style and added a fleece flower with pearl accent to close the envelope. Stylish and affordable since I recovered an existing pillow with a sweater purchased from a church rummage sale for a dollar.