I know I'm late to the party here, but It seems like Bass Pro had some good female clothes for concealment - looser fit, longer coattails, etc. [Beer]
I have a few different holsters that I use IWB between 3:00-5:00, but I'm still struggling to find something that is as comfortable as I'd like. I wear a crossbreed supertuck when I'm dressed down, but I use an Aliengear cloak 2.0 when i'm dressed up (I wear a suit at least once a week).
When I'm dressed down, I just wear jeans with some sort of loose-fitting workout type shirt (I love the Nike Pro Combat shirts for both working out and lounging around). Most of the time, one of those shirts is enough to conceal a Glock 26 at 4:00. Conveniently, my new climate is cooler for a good portion of the year, and I have a couple of cheap zip-up sweatshirts and jackets that I can always throw on for extra concealment (especially since being "discovered" here would be a significant problem).
When dressing up, even with fitted dress shirts, it's super easy to conceal. Shirt gets tucked in over the gun as Irving said in post #5, and suit jacket provides extra cover. If anyone mentions anything, it's usually a compliment on the suit. A few times i've been asked (halfway-jokingly) by friends why I always wear a suit to church... And it's an easy and obvious answer that I like to dress up to go to God's house (which is true). Nobody could possibly question that, right?
I do think I need to find a good OWB holster for wearing around the house when I'm not interested in concealment.
ETA: I almost forgot one of the most important parts! My BELT! I don't have a "Gunbelt" but I think this is pretty darn close. I picked it up about 6 months ago from a Kohls store in Michigan. It is made by Columbia and is a very firm leather belt that feels as though it has a plastic or springsteel core. No more sagging pants on one side! :D