I have achieved my Amecon cosplay goal - having a more-or-less completed costume finished in less than a month!
OK, it's not completely finished just yet - I still need to make the gold embellishments (probably using applique) and finish off all the seams with bias binding, and I need to put some hooks and eyes in the back of the collar, but as of this afternoon I no longer have to make or attach any other bits to the dress itself in order to call it a whole, wearable dress. I am very pleased with it, and sure enough, my favourite bits are the sleeves - they're lovely and puffy and I think the cuffs look great (which is especially good because I screwed one of them up pretty badly the first time I made it).
You'll also notice that some work has been done around the skirt. You can see the front in the above photo; here's how it looks from the back (note that this is an older photo and the cuffs haven't been put on the sleeves yet):
I'm not actually sure the back of the skirt hangs down quite as long as I'd like it to, and it makes that raised bit in the middle look a bit too short, but it does all make proportional sense when I'm wearing it (if that raised bit had been any higher I'd have been showing off my butt whenever I walked around, and I intend to be a modest Chun Li).
My tasks now, apart from the aforementioned messing about with gold fabric, involve finding some suitable boots (white, knee-high, laces up the front, slight heel, and not made from patent!), making the sash, and figuring out how to make the spiky bangles. The good news is that I have an idea of how to do that last bit; the less good news is that I'm not sure how workable my idea will actually be. But we shall see.
And now I can start looking at my other two Amecon cosplay projects...