Clothing was neat and tidy and most of all practical. In the 1930s the emergence of "sports wear" (now we refer to it as "ready to wear") became popular. Women became much busier and worked more than before therefore the need for clothing that allowed easy movement throughout the day was much needed.
Glamour was reserved for the evenings. Gowns with a low cut back were very popular. (Think Keira Knightley's green dress in 'Atonement') Fabrics that were popular included chiffon, silk, crepe-de-chines, and satin cut across the fabric to create gentle fluidity in the garments.
Sources: Nearly all these images were scanned in by carbonated on Flickr. A couple are from Etsy (sorry, the images were saved awhile ago, so I don't know which profile they are from)