I am setting up a Firefly birthday and I made this dress as a prop in the Kaylee's bunk-themed room.
This instructable is fairly easy to do and very cheap I might add.
Step 1: Cardboard Cutout
To make this prop you will need :
A large piece of cardboard - at least 5' x 4'
Magenta, Pink and White crepe paper
White and Pink spray paint
The first step is to cut out the dress shape. to get the top symmetrical I drew half a dress on a folded piece of paper then cut it out and unfolded it and traced around that paper template. Use a utility knife to cut out your dress shape. Mine ended up being 5' tall and about 4' wide. It will be hanging up and not worn so just try to get close to the size a dress might be.
Step 2: Spray Paint
To help from the cardboard showing through the crepe paper, first spray it with a coat of white spray paint. If you have pink spray paint, you can also paint the skirt portion pink. If you only have white, that will work fine too.
Step 3: Hang 'er
After the paint is dry affix the cardboard to a hanger. I had the best luck with clear packing tape to get it to hold.
Duct tape does not work :(
Step 4: Adding Ruffles
Start at the bottom and start adding strips of magenta crepe paper. A glue stick works like a charm for this. Drag one stripe of glue across the skirt bottom then add your crepe paper (Leave it on the roll for now). As you stick down the paper gather it to make ruffles. Not so different from doing frills on piñatas. When you reach the end snip it off.
Build up on that layer 1/3 up the skirt then use pink for 1/3, then finish with white.
Step 5: The Bodice
The bodice is a little trickier.
Start by adding glue and then take a strip of white crepe paper and gather it horizontally. Keep adding white paper all the way up the bodice excluding the sleeves.
The sleeves are the magenta color. Add strips following the curve of the sleeve.
Finish the sleeve with a horizontal strip and gather. Finish the sleeve by gluing a strip of twisted white crepe paper as shown.
Next, Add the magenta strips that go up and down each side of the bodice. I simply just folded a strip of magenta crepe and glued it in place. Then, you can do the collar. Again, I folded it in half and cut scallops shapes along the strip. Then you can glue the strip going down the middle of the bodice. Finish the bodice with the magenta belt which is two strips of half folded paper.
Finally add a few buttons down the front.
Step 6: Bonus
The parasol was a purchase from thinkgeek.com.