I made my daughter's first princess dress out of a dress that I stopped wearing. I save a lot more ill-fitting, stained, or damaged clothes than I used to. If I like the fabric, I try to think of something else that I can make from it. I don't have a before picture of the dress, but it was a very basic, 3/4 sleeved, knee-length sheath, which made it the perfect length for a long princess dress.
I took it in a little bit, added elastic at the waist, draped tulle for poofiness, and added a tulle neckline. I was able to preserve the original hem...it's always nice to be able to cut out some steps!
I found this sparkly button in a stash that my mom gave me years ago that is the perfect embellishment for the new neckline.
I also cut up a very old and worn out Elizabethan costume that I inherited. I had just enough fabric to make a Tinkerbell costume. I used one of my daughter's undershirts as the lining and cut the green velvet to fit comfortable over the undershirt. I made straps to cover the ones on the undershirt as well. I cut up 6 or 7 leaves out of the velvet with a couple of layers of green tulle on the top of each. I topstitched leaf veins as well. It was so easy to use the undershirt as a guide. I'll share a couple of other dresses I made with undershirts another time.