I didn't intend for this project to be a no-sew, but I'm an ambivalent crafter. I removed the sleeves from an extremely large silver polyester top and couldn't decide whether to turn them into a fabric corsage or a ruffled collar. So I tried pinning on the collar. And it looked OK. So I'll wear this for awhile, then pin a corsage, and then someday I'll make up my mind and this will be a sewing project.
For all of you out there who lack thread or decision-making skills, here's how to do it:
I started off with a free tank top and a free blouse in a complementary color. Look for a blouse with a silky texture.
I removed the sleeves and took advantage of the fact that they were already sewn along one edge. I bunched up the fabric at intervals of about an inch or two and safety-pinned the fabric to the collar of the shirt - one sleeve for the front and the second sleeve for the back. I tucked the raw ends and the cuffs under.
To make this permanent, simply hand-stitch the gathers to the shirt and remove the pins.