Sometimes, the easiest (and funnest) way to lengthen a dress is to choose a contrasting color. Store-bought clothes incorporate color-block bands at the hem all the time, so don't be afraid to try it yourself and wear it with confidence. This works really well, especially if you've already seen a version you want to imitate. The idea for this project came from a Ralph Lauren dress using the combination of navy and green and works like a dream if you're only needing about three to six inches of extra length.
Determine how much width you need before cutting. I used a five inch wide band to allow for hem allowance.
Always take the original hem out of the dress before adding a band. You want the bottom of your dress to flow rather than hang stiffly from all that bulk.