Start with a straight shapeless dress with short sleeves or no sleeves, and add fringe to the skirt or all the way up. You'll also need a small, close fitting hat. Add a feather to the front or a jazzy hat band with a big bow. Wear dark stockings and flat clunky shoes. Your accessories will make the outfit. Things like a feather boa, bangle bracelets and a long string of pearls tied in a knot are very jazzy. Wear your hair in a short bob.
Get an over-sized, double-breasted suit from the thrift store--look for stripes, plaids and bright colors. Look for fedoras, vests, ties, shirts and shoes in contrasting colors. Coordinate colors, like a navy and white-striped suit with a navy shirt, a white tie and navy shoes; a yellow and black suit with a yellow shirt, black tie and shoes; or a white suit with a black shirt, white tie, and black and white shoes. Add a carnation to the lapel.
Create a dressier look for a night out on the town by using a rich fabric to form the same basic straight, sleeveless style as the flapper dress. Don't add any fringe and make the hemline a little longer than the knee. Add more pizazz to the hat and more flash to the jewelry. Dress up your guy in a black or white suit jacket with a bow tie. This is also the outfit for Jazz Era musicians.