If you have a hard time finding clothes that fit you perfectly at adult or even teen stores, it's time to check out some kid's place. No, that doesn't mean you have to dress like you're in fourth grade but you can score some great deals on basics that will fit and flatter!
My favorite kid's store is Abercrombie Kids. Thier sizes are meant for the typical 8-14 year olds, but smaller ladies can definitely fit into their larger sizes. If you like A&F jeans but hate the prices, check out Abercrombie for similar styles at half the price. If you're a little under 5 feet tall and have a 22.5 to 24 inch waist, you'll probably fit into a 12 regular or 12 slim. If you're between 5' and 5'3 with a 24-26 inch waist, you can fit into a 14R, 14S, 16R or 16S. And none of their jeans have anything childish about them; they're just slightly smaller, cheaper versions of A&F's classic styles. If you've got small feet, they have that covered, too: all their flip-flops are currently on clearance and with sizes ranging from S (5/6) to XL (8/9), you're sure to find the perfect pair for you. They've also got great outerwear that's easier on your wallet than at Abercrombie & Fitch. Their Taryn faux leather jacket ($99.50) looks like the real thing but won't cost you an arm and a leg. Stick with the large and x-large sizes because you don't want tops that are too tight in the bust area.
Anothe great store is 77Kids, one of American Eagle's brands. Sometimes, AE runs a little big in the bottoms--I have a few pair of denim crops, shorts and jeans that all fit in a size 00 (some are even too big!) Plus, their short inseam may not be short enough for those of you under 5' or with shorter legs. 77Kids has similar jeans (they even have jeggings!), though some you may want to avoid, since they have sparkles or bright pink stitching. The skinny jeans aren't quite as skinny as AE's though, but that may suit you just fine. Stick with just the jeans here, because most of the other pieces are obviously for kids.
Don't be afraid to shop kids clothing--it'll save you money and may fit you better!