Looking good is always affected by the outfit that you’re wearing. Don’t confuse it with wearing expensive clothes because it is totally a different story. You don’t have to take fashion short-courses in order to pull off that glamorous outfit.
Everything can be learned, all you have to do is be observant. Make yourself aware of the colors that looks good when combined, as well as those that don't. Familiarize yourself with the color wheel and choose colors that belong on the same group. If you can master the mix and match basics, then it’s a guarantee that you would be wearing an outfit that isn’t going to be eye straining.
You don’t have to buy the entire outfit in one store. Learn to hop from one place or store to another and compare prices. Sometimes sidewalk boutiques got the widest selections in town. These are also the type of stores wherein you can bargain for prices if you’re going to buy a lot.