Sheer fabric (enough to wrap around your body twice and long enough to reach from your ribcage to the floor) I picked up 5 or so yards of this fabric at a thrift store...score!
2.5 inch elastic (enough to fit around your ribcage, below your chest) I dyed mine yellow using this tutorial: MADE: Dying Elastic
The skirt could be attached to a tank top or close fitting t-shirt to create a dress. I only chose to leave it as a skirt because I wanted to be able to wear the tank top on its own or with other things.
Then, enjoy your light and airy skirt (of course with a slip underneath it...it is sheer after all :)