There have been a few posts that sent you off on a hunt for the cabaret style bellydance costuming.
Modern cabaret costumes come in a variety of styles. If you are looking for something authentic to a specific time/ethnicity/dance style you need to be pretty knowledgeable. If you are American, and looking for an “American Cabaret” style costume, you have a LOT more leeway in decision making (and in embellishment).
For this reason, and because nothing I dance is likely to be completely authentic – as Saqra says, I will always dance with an American accent, I tend toward mixing and matching almost willy-nilly. There are still a few conventions I follow, however.
Egyptian Raqs Sharqi. This format is demure not so much by original nature, from what I can learn by reading, but by law. Egyptian law has mutated over the years to specify what dancers can wear, who can dance where, and how much leg can be displayed in Cairo. Stomach coverings and long skirts with very little slit (so as not to show much leg) are de rigeur. This does NOT preclude the “big names” such as Dina from fiddling with this and pushing the envelope.
Egyptian costuming has two different basic variations: the bedlah, or “uniform” which is generally the two-piece costume (with a stomach cover) that we know here – the bra and belt set over a skirt, whether straight or full, and the beledi dress which is a one-piece, evening-gown or caftan like garment used primarily for the more folkloric styles – for example, dancing with a cane.
Turkish Danse Orientale: This format can be much more “out there,” possibly because of the secular nature of the Turkish government, and possibly simply because the Turkish dancers have a more sexual take on the dance form. In my experience, movements are bigger, costumes are smaller. Music styles are different, there are more unique rhythms involved, including time signatures of 5/8, and 9/8, and the instrumentation is different.
American Cabaret: this format combines bits and pieces of all the other formats, and the costuming reflects that. Beads, side slits in the skirt, harem pants, heels or bare feet, and other shinies. The Americans added and expanded on the use of props in the dance. Here you’ll find sword work, veil work, candle dances in various formats, and all manner of gimmics. Costuming often varies depending on the prop used.
Tribal costuming and beadwork techniques covered later. 😉
There is a wonderful description of various costumes at Atlanta Bellydance.