I normally wear a size S, but after reading the review by A. Faris, (who claimed that even her "skinny teenaged little sister" couldn't even fit into the M/L) I decided to get the M/L. But much to my disappointment, it ended up being too big for me. Nothing a little re-sewing can't fix, but take it into consideration when purchasing.
On another note, it needs ironing but the fabric is comfortable and gorgeous. The dress isn't too short, but the cleavage is so open that it ends up showing even my bra. (Maybe because it's too big.) Very sexy and cute.