Thank you so much for all of your comments! I tried it with a petticoat and while it looked much better, I felt incredibly uncomfortable in it. I'm not sure if there's actually going to be a way to get to something I'm happy with from the original pattern.
I'm tempted to leave salvaging this one for another time and just make something simple out of the offcuts for the party, I have a couple of tried and tested patterns I could run up quickly. Or the other option is a black strapless dress that only needs a zip putting in and hemming (started 3 years ago so not quite as old as the prom dress!). I don't really have much else in my stash or ufo pile that would do for this.
I have plenty of time to sew but I need to finish my partner's outfit too, although that can't be fitted until next week.

I first posted about this dress on TSF years ago when I was making it to wear to prom and it turned out that attempting a complicated pattern (or even a simple one involving so much fabric in the skirt...) during exams was not a good idea. I ended up going with the side seam pinned together and the neckline and skirt hem finished by melting the raw edge over a candle (I'm not joking) and the neckline details missing. Then I hid it at the back of the wardrobe and pretended it didn't happen.

But now I need a dress for a party so I've taken it out to see if it can be saved. It's V1094 and it really didn't suit me. I took two panels out of the skirt but even then it swamped me and the gathering on the skirt is uneven and messy. It also has a dropped waist which I would never normally wear, made worse by the fact that the waist was too loose and made me look shapeless. The internal construction is a mess and absolutely nothing is finished properly. I'm thinking the best plan of action is to take is to take the skirt off and remove the lining. I'm going to attempt to put the neckline bands on properly because that's the detail that originally drew me to the dress. I'm not sure whether to try to salvage the skirt by redoing the gathers properly or to try to cut a new one from the pieces - normally if I'm wearing a full skirt I prefer circles or part circles, and I could maybe squeeze panels to make a circle from the existing skirt pieces. I still have the two that never made it into the skirt plus some other bits of extra fabric. Whatever I end up doing will be attached on my waist instead of below it and hopefully the final product will be something I'm happy to wear without fear of it disintegrating if I move. And if it doesn't work then at least I was only trying to salvage an earlier disaster! I've attached a photo of it from the day of the prom as a before, and now the unpicking begins. Any ideas for ways to rescue it would be greatly appreciated!

Thank you Vegegrow that's a really good idea! Her work is stunning isn't it - the ensemble costumes for Wicked are great too, all asymmetrical and odd looking. The bubble dress is one of the only symmetrical costumes in the show, Glinda has some wonderful outfits including a suit jacket with one sleeve and diagonal buttons.

I've long been an admirer of Susan Hilferty's wonderful designs and I've made a couple of dresses inspired by her work on Wicked but this is the first time I've attempted a full replica. I remember people on TSF being really lovely and supportive so I thought I'd start a thread here for when I need a gentle kick up the backside to keep sewing sequins on! Also I love seeing other people's work so hopefully someone will enjoy reading about this.

The first thing to do was to collect sequins. Each dress is slightly different but they all have approximately 70,000 sequins on the skirt petals and bodice. They've come from a wide range of sources including unexpected finds at the rag market which turned out to be a gold mine for cheap sequin trim and massive bags from poundland. I think the current collection of sequins is about half of the total needed.

Fabric wise, the skirt is sorted. It's sheer iridescent fabric (similar weight to organza but it doesn't quite feel like it) with pale blue organza over the top and white tulle over that which the sequins are sewn on to. The bodice is holographic lycra with blue power mesh sequinned and then streched over, both ordered but haven't arrived yet. The original dress has massive petticoats but to reduce the weight and cost of the skirt I'm using my hoops with a couple of layers of petticoats over the top. The movement won't be quite right but I think it's a worthwhile compromise.

Progress so far is an attempt at drafting the skirt petals and pinning them onto the hoops. They don't quite look right as the middle layers are too narrow and the skirt isn't full enough without the added petticoats but it's a starting point. I've tried to attach photos of everything!