You don't have to blow your entire budget to give your wardrobe a classy upgrade. Instead, invest in a few key pieces that can transform any outfit, and concentrate on how the clothes look on you, not on their price tags.
For example, Tiffany Yannetta, shopping director for fashion website Racked.com, recommends splurging on a high-quality blazer.
"Buying a good blazer is important because it's such an easy way to elevate an outfit," Yannetta tells CNBC. "The upper half of your body is what people see the most — more than your pants or your shoes."
Footwear can be important, too, though. For Fredrik Eklund, a self-made millionaire and the star of Bravo's "Million Dollar Listing," shoes make or break a professional outfit.
"Everyone notices your shoes," he writes in his book "The Sell." "What's on your feet can either give you a strong leg to stand on or hobble an outfit."