The key is really developing an eye for what looks good on you; then you can apply that knowledge no matter where you shop. These days, I do a lot of my shopping at Fashion Bug; I've gotten a number of lovely and flattering things there, and if you buy mostly clearance and "priced just right", it's really not that expensive. (I also have a credit account with them and I pay $25 a year for the premium thing that gets me extra discounts and tons of good coupons.) But I've also found lots of great stuff at Walmart.
Because you are a bit shorter than most clothing is designed for, pants probably run a bit long, but the bright side is that shirts probably run a bit long, too, and that's good. I don't wear shirts that are higher than the tops of my thighs, and frequently shirts are just a bit short for my taste.
Know your measurements, and check sizing, because makers can vary widely. One of the pant makers at Fashion Bug, for example, has an inseam for average that most pants have for tall, and I'm best off with their petite sizes if I don't want to walk on my pants. :P This also will enable you to shop online/through catalogs better. Lane Bryant Catalog (NOT the same as Lane Bryant) sells a lot of stuff at good prices, particularly, again, if you watch the clearance section.
Try stuff on that you normally wouldn't; if you can, get another pair of eyes to help choose things to try on with you. Shopping for clothes can be a serious workout and draining, but it pays off when you have a wardrobe you are truly happy with, especially if you choose pieces that won't become dated too quickly. Also, when trying stuff on, assess all the aspects of the clothing; maybe the print/color is all wrong, but the cut is fantastic; file that information away and keep an eye out for the piece that has all the right components.
I'm going on and on, but, then, I've spent a lot of time on figuring this stuff out. *grin*