For kids' cotumes, I had the puffiest clowns and and the chubiest witches in the world. Then when the holiday was a bit warm, they still managed look a bit sagggy but still OK. Yes, I sewed their costumes with sweatshirts or snow jackets in mind. And, because the kids were two years apart, the costumes managed to last for about four years! Then, passed down to my sister in law. Still proud, however, the kids never asked me for my secrets, so I guess I wasn't so good after all.