One of my college friends was living in Mexico when Little Sister was born, and she sent me a beautiful embroidered dress for a baby gift. It was too big, so I put it away and was so excited to pull it out recently. It fit Little Sister perfectly and looked SO GREAT on her! She loves it too--as a matter of fact, I put it on her just to see if it fit, and it was a typically Portland chilly rainy day, but she wouldn't let me take it off of her.
SO, I found a piece of fabric in my stash that matched pretty well and made a little keyhole opening in the back, right between two embroidered bunches of flowers. Now it's got a sweet detail that will allow Little Sister to wear the dress even after it becomes the size of a shirt on her! Yay! Simple, quick, practically free, and probably doubles the lifespan of the dress.