I found a great post on how to take measurements of Vintage Clothing at Wickedly Divine Vintage.
At The Vintage Effect, all of our garments are placed on a flat surface to be measured. The bust, waist and hip inches are then doubled. The best way to ensure a good fit is to compare the measurements of a garment you are interested in buying to those of a similar piece of clothing you already own.
To be safe on your sizing, it is a good idea to add about an inch or so to your measurements when comparing them to the measurements listed on our site. That way you know you'll have some room to work with. If you receive an item and the fit is completely wrong, we will offer store credit for the purchase price.
Lastly, if you have any questions at all about sizing, just email us! We'll try to answer your questions before you make a purchase. Our email address is firstname.lastname@example.org.