For my fabric, I used thrifted white cotton sheets of mine that were going to be thrown out because of some holes (that my persian cat left when using her back claws) but last summer I insisted on keeping the sheets with hopes of making some kind of nightgown later on. Why save them? The cotton fabric is THE most softest I have ever felt, and I love the way it feels up against my skin. =) And besides, I was able to avoid all holes save one very small one!
Using the Elegant Ladies Closet "Crossover Gown" pattern as my base, I cut off the needed amount in front to where it wouldn't cross over or be overly "blousey." For the back, I used a muslin tester that was sewn with the two back pieces, and just made the back bodice without the princess-seams. Oh, and I added/deducted an inch from the shoulder seams to bring the gathered shoulder closer towards the front.
I wanted to be careful that the neckline wasn't as low as my inspirations, but not to high to look weird, but it came out just right. I added just a few gathers in the front "V" area, and added some trim to that, and the empire waistline. I also gathered the front instead of doing the pleats. In order to get it on and over me, I had to make it quite roomy, and then add soft-stretch elastic to the waist.
It looks MUCH better on me, and far more like the nightgowns on the films than it does on Arabella, but this picture gives you an idea of what it looks like:
The sleeves, which did not come from either inspirations, were done on a bias and I added 12" more to the hem sides of sleeves to make them in a "bell" shape (I wasn't able to capture a good picture, unless the gown was on yours truly). The hem of both skirts together is as wide as a two top sheets, (since I used one hseet, cut it in half, and wala - my skirts!) so you can imagine that my skirts are very full, but yet feel very light and airy. It did help by narrowing the top part of the skirt and then flared it out. Otherwise, I'd look like a hot-air balloon in it! =D