WATCH fitting girls at victorias secret, i've found more times then not they DON'T know what they are doing.
I lived in Chicago and was very lucky to have bra boutiques, if you are in a larger town see if one of those are around, other wise I prefer Fredrick's of Hollywood over VS on comforter, price, and costumer service.
Haven't tried Soma i'll have to see if anything is in my new town.
If you can buy online and know your size I love fig leaves
http://www.figleaves.com/ (just watch the bras some are flimsy and some are supportive.
edit: 36DD so a good supportive bra is love!!!
Edit x2- you have two shops in dallas
http://www.trousseaudallaslingerie.com/ and
http://www.myintimacy.com/ hope that helps