Many sites have software that allows you to place your chosen items on a virtual body as well rotating the item so that all sides are visible. In addition, the software can bring you in closer to see the detailing and quality of the ware. The plus here is that if those shoes you want that will cost you your entire month's allowance, they are probably tax free. On some of the more popular sites, shipping is free, too. The person who succeeds in sporting the latest trend will most likely draw inspiration from the catwalk and then take to the streets mixing articles from new and vintage boutiques alike.
Confidence is key as is knowledge of the current trend.
Be sure to do your homework. And remember, fashion, like beauty, is in the eye of the beholder. If you are confident with your personal style, no fashion house rule should change you. Individuality is what brings trends to the forefront. Who knows, something you're wearing today might inspire the next Tom Ford or Jil Sander.