Finding a dress that looks polished yet feels comfortable to wear all day is a total wardrobe win. And if it also flatters your waist and pairs perfectly with sneakers . . . even better! That easy, chic balance is exactly what makes these classy dresses fall into the "throw-on-and-go" category. You'll look put-together without even trying. From tie-waist dresses to pleated midis and flowy wrap styles, we rounded up 19 Amazon dresses that instantly slim the waist while keeping things casually cool.