Colonial Yarn Shop offered a class in making one.The sweaters in this book "Knit,Swirl" by Sandra McIver were all the rage last year and I got interested in making one when my favorite yarn shop
or "upside down" with a large collar and shorter length (which I actually liked better)
I decided to SEW the body of the sweater to go inside the circle, using a simple rectangle folded to make the sleeves. I auditioned several fabrics from my stash and here's the wool fabric I decided on, some left-over felted wool from another project. It did seem to match one of the sweater stripes better than is shown
in the picture.
Since I wanted the body and sleeves to be loose and flowy I used the folded rectangle method for it, sewing the edges together a little way for sleeves, and sewed the complete outside to the inner circle of the knitted piece. I later serged the seam to look better.