This dress is based on one I found on DIYStyle (link below). They made theirs a maxi dress whereas i chose to keep mine knee-length. The "origami squares" at the top are a cute and interesting touch and scrunch up when the dress is finished.
On the DIYStyle website, you will find a link at the top that says "Vodcasts." If you click that and then scroll down to episode 50, you will find an instructional video to help you make the dress. They say you need to have made a previous item on the website to make the dress but it isn't true. You can just use a tank top to help you get the arm holes right.
For the armhole casting, I simply folded them over and hemmed them instead (much faster and easier and with the same result). For the neck hole with the scarf, you just fold the top fabric down 1.25 inches and sew. It's that easy!
Good luck and have fun! :3