Follow your "gut" instinct. When it comes to fashion, buy what you love and not what everybody else says you should be wearing. Granted, there are some things you may love but because of your body shape you should not be wearing.
Follow the trends, but don't be a slave to them. Mix trendy pieces with classic pieces or mix old trends with new trends. This also saves you money because you don't have to go buy a whole new wardrobe every season.
Don't spend your money all in one place. Sometimes it's ok to wear a whole outfit by one designer, but it's more fun to mix it up.
Recommended Readings:
from a Fashion Pro on Creating Your Own Look
Building and Improving Your Wardrobe Piece by Piece