I am a very sloppy and impatient seamstress. I cut important corners like ironing and basting, yet the end result here still looks great. This muff took me less than 2 hours to make and cost me nothing, because I used an old coat too ugly and stained to donate, and a scrap of fabric I had lying around.
Step 1: Materials
Any heavy fabric will work. You can use velvet, fake fur, or even real fur if that's your thing.
Step 2: Cut
Although I gave dimension in the last step I did not actually make any measurement while I was sewing this muff -- I really meant it when I said I was a sloppy seamstress. I just threw my coat on the floor, and eyeballed the approximate size. Since my old coat had become quite thin and limp I decided to double it up, so I drew a rectangle with a chalk around 30" by 16"
Do yourself a favor and do not repeat my mistake: I sewed along my chalk line to avoid loosing all the feathers in my rectangle, but I forgot about the other side. The coat was so thin I didn't think there would be too many feathers -- boy was I wrong! I attempted to staunch the flow of feathers with masking tape, and ended up wasting much more time than if I had simply sewn another line, one inch from the first one, and cut between the two.
To measure the right size for the outer fabric I folded my lining in two, placed it over the fabric and cut another rectangle, leaving about an inch extra on all the sides to allow for the material to be tucked in and for seams.
Step 3: Sew the First Side of Your Cylinder
Place the right side of the fabric against the inside of the lining (meaning the side of the lining your hands will be touching when you use the muff). Sew the lining and fabric together about 1/4" to 1/2" from the edge of the long side of the rectangle.
Flip the fabric around so it is right side out and it hides the seam you just made, as shown in the last picture of this step.
Step 4: Form the Cylinder
1. sew the lining to the fabric on each side separately (i.e. you will still have a rectangle, not a cylinder), then fold it in half, right side out, and form a cylinder by sewing the short sides of your rectangle together by hand.
2. sew the lining to the fabric on each side separately (i.e. you will still have a rectangle, not a cylinder), being careful to leave extra fabric on the edge. Then fold the rectangle in half with the lining side out and with your machine sew just the two layers of fabric of the short edges together. The disadvantage here is that the seams you made to attach the lining will be visible.
Step 5: Sew the Second Edge of the Cylinder
Curl the fabric around so that it folds inside the muff. Fold the edge to hide it inside, and sew the outer fabric to the inner lining by hand.
Step 6: Finishing Touches
It would be fairly easy to make a strap either with a strip of fabric sewn on by hand, or even with a small chain purchased from a hardware store. I leave it to your imagination.