Have you chosen your Halloween costume yet? Have you bought it/made it yet? If you wanted to be Audrey but haven't been able to decide which version of Audrey to be, don't fret. You have plenty of options.
You can visit my older guides (part 1, part 2), but I have also found two newer books for the more crafty among you. These books offer instructions and patterns copying famous film costumes, and while they won't be precise replicas (because that would involve some fancy couture sewing!), they are quite nice replicas that you can use as a costume or even just in everyday wear.
Sew Iconic, and features a pattern for Audrey's little black dress with the fringe from Breakfast at Tiffany's. This dress is a bit easier to make than the long column dress from the beginning of the film, and makes it easier to walk around all day (or climb out windows, if need be). If you're a big film buff, you might also love this book because it features Marilyn's iconic Seven Year Itch dress, Keira Knightley's green dress from Atonement, and Catherine Zeta-Jones' nightclub dress from the opening number in Chicago. If you'd like to get a better feel for the book, the foxling has a wonderful review with loads of pictures.
Famous Frocks, is more of an eclectic mix, featuring the same Breakfast dress, along with a Twiggy mini dress, a Farrah Fawcett shirt dress, Madonna's Like A Prayer dress, and a Rita Hayworth costume. A blog with the name of geeksdigme has a post with more pictures and some additional information, if you wanted to have a better look.