Some of the classics include the 2-piece suit for women that was structured, with a mid-waist hemmed jacket and a skirt with a hemline just under the calf. This structure and the visual lines of the waist was opposite from the 1920's boyish cut, flapper era.
Other classics that were born in the 1930's include the white blouse, the shirtwaist dress, cloche hats, gloves and the introduction of the bias-cut for evening gown dresses.
Designers were forced to use cheaper fabrics for their creations as women during this hard, economic time could not afford what they use to. Two of the most influential designers of the 1930's include, Coco Chanel, creator of many classics including the "little black dress" and Elsa Schiaparelli, one of the most daring designers of the decade.
The 2-piece suit was created with comfort in mind and was a symbol of power and hope for the active woman. Movies also had a great influence in fashion as it was an "escape" for most from reality. For Coco Chanel, the wool jersey suit was one of her most famous innovations aside from her iconic Chanel No. 5 perfume.
I personally love vintage fashion from the 1930's and 1940's; I feel it is one of the most beautiful times in all history when it comes to fashion.