This little dress took me 15 minutes, at most. I'm glad it only took 15 minutes, because I don't think I could have been patient with the "is it done now"s I was getting for too much longer. ;-)
I used pre-shirred fabric, and wide grosgrain ribbon for the ties.
My daughter thinks any dress is a princess dress, but this dress is doubly a princess dress with the Disney princesses along the bottom.
I have made shirred sundresses before (see here and here) but pre-shirred is definitely the way to go! So much less time-consuming!