I used a stretch knit that draped really well and didn't unravel.
First I started with the top of Butterick #5001 and modified the sleeves. You should note that I have made this one before and I have modified how I put it together to give me a better fit. Also for this particular top I modified the back to be more scoopy as I intended to wear it off the shoulder which only sort of panned out.
This pattern has a 3/4th sleeve. But I wanted something longer and more flowing. This is how I modified the sleeve pattern. I did it rough without using a ton of math or precision. It is worth doing again only in a more clean way. The fit was nice.
Then instead of putting the skirt on it I put a very short circle skirt on it... I wanted that frilly look. Now I made the circle skirt a bit bigger than the circumference of the top and I gathered it in the back to form that bustley look.
This is how the math broke down (click the image to get a bigger look and readable captions).