I've used polyester double knit to make quilts for dogs ... not very fancy, but they are interesting and almost indestructible as they go through weekly washings. I also made one for a lady in a nursing home for the same reason (it was made from clothes that had hung in her closet), but don't know what happened to it after it walked away. As others say, keep the pattern simple. I tied some of them and then tried stitching simple designs where fabrics met in a couple. Easy and quick projects.