Strapless Bubble Dress
This classic and conservative cotton dress can become really edgy -- for just a night, or the rest of its life -- with little more than a yard of chiffon. "We used the dress as the structure under the chiffon, the way a hoop skirt is 'the cage' under a dress," Katie says. This wrap treatment works best with a sleeveless dress with a straight skirt, or a slight A-line, as shown.

What You'll Need
Strapless knee-length cotton dress
2 yards of chiffon (45" ombre silk georgette, $24.95 per yard, from N.Y. Elegant fabrics, 212-302-4984)
Needle and thread

Bubble Dress How-To
1. Cut the chiffon to one-and-a-half times the measurement of the hem's circumference.

2. Starting at the zipper in the back, fold the chiffon over the upper edge of the dress, and pin in place.

3. Work your way around the top, slightly gathering the fabric and pinning in place. "This is a very approximate process," Katie says. "You have a lot of leeway, so it doesn't have to be perfect."

4. When you reach the zipper again, be sure the fabric does not overlap it, otherwise you won't be able to get in and out of the dress.

5. Try on the dress to make sure you like the way the top looks, then take it off and sew the chiffon onto the dress. Stitching from the inside, through the inner lip of chiffon and the cotton of the dress, but not through the outer layer of chiffon.

6. Repeat the same general process at the hem. Drape and slightly crisscross the vertical edges of the chiffon, so they cover the zipper. Try on, and stitch in place.

"Mogul" patent heels, $330, by Bill Blass (piperlime.com)