I have, many years ago, I used two feather pillows to stuff it with. Never had such a mess in my life .
I made two mummy shapes ( the inner one was 1" shorter & narrower all over) and then sewed them together from the feet up in rings about 6" apart. I left 2" open in each ring and then stuffed each ring seperately and closed the seam by hand. I had feathers erupting everywhere
Finally finished I was quite chuffed with my bag, well once I'd emptied the hoover half a dozen times, I was.
I used polycotton for the bag (it was what I could get
) and it worked fine for about 2 days, then I got up looking like a dandelion
It was warm though, and it just shook back up to loft in no time at all, but I couldn't stop the feathers coming out. Eventually it became the cats bed and got binned.
If you are going to use feathers buy "Feather proof ticking"......me? I'll buy one from Outdoorcode
Best of luck with it.
Cheers,
Toddy