I sometimes buy from Blair online. At one time their clothing wasn't up to my standards because the fabric was cheap and workmanship shoddy. However in the last few years, the have been offering quality products and also petite sizes. Their clothing is very affordable and I especially like their jackets and blazers. Just don't buy their $9.99 pants to wear to the office. They tend to run out of some things quickly, especially sale items, but they have a good return policy. They frequently offer free shipping as an incentive, even on sale merchandise.
I also have shopped at Catalog Favorites and Serengeti when I want something a little out of the ordinary. Serengeti doesn't run very good sales, however, so I have to want something really badly to order from them, and their shipping is high. I haven't sent anything back to either of them. The downside to these two companies is that when you place an order, you will be deluged with catalogs from unsolicited other companies. I keep trying to unsubscribe to one company and explain that I am not a Women's Plus size and they don't carry size 6-8 petites.
For shoes I like Auditions because they carry quality name brand shoes in hard to find sizes. I am a 6N in shoes and boots, but I can wear a 5M in sandals. Again, shipping can get you with shoes if they don't fit. I tried Zappos but the shoes appeared to be seconds.