Antique Lilac sells dresses, as well as offers tutorials on how to make outfits. An excellent site with a beautiful gallery for design ideas. I know it's a doll, but what an amazing fairy costume this would be!
So, I came across this pin a while back, and it led me to Ayyawear. It's a small, super-high-quality clothing brand specializing in apocalypse/steampunk styles. Their clothes are absolutely amazing! ^^^ whatever this is legend of korra steampunk