When? I made this for Comic Con 2010. I came second in the skit contest: pretty good, huh? My skit was Violet's monologue from one of the teaser trailers.
How? When I made this costume I was still quite an amateur when it came to sewing. The Costumer's Guide to Movie Costumes was the most useful resource while I was sewing it, because it contained a detailed guide on how she made the costume.
I started off by making a very very basic bodice (this bodice tutorial) out of muslin. Then I added on bits and pieces of fabric and hacked away at it with scissors until I got more or less the right shape. Then I cut it out in purple cotton and organza, and sewed the bodice and circle skirt. It was tricky because the ribbons had to be sewn to the organza before sewing the cotton and organza together. Note to beginners: try not to use organza when you are first learning to sew costumes. It is difficult to cut, and frays a lot. The hardest part of the costume was appliqueing the weird embryo shapes on the skirt: sewing organza to organza (with the help of a lot of fabric glue). I cheated with the eyelets and bought eyelet tape. I altered a pair of boots to look like Violet's.
Has it aged well? Surprisingly well, although it sometimes makes me cringe a little because I can see all of my mistakes. The worst is probably the glue stains on the organza, and the waistband. I messed up the skirt and made it too tight, and had to add elastic to the waist to make it close. The costume isn't totally accurate but considering my skill level I think it still looks very good, though it's more or less retired.
Would I remake it? Yes, but I would use different methods, and try and get it as accurate as possible. If I have the money and time to make it, then I will, because I still love the character and the design.