Target's Fall Premiere provides some excellent examples of this. check out the amount of clothing the women are wearing; shirt, dress, cardigan, and belt.
above are photos from JCrews Fall 2010 look book. notice the amount of layers used and the dimension it creates.
your assignment, if you choose to accept, is to head to your closets and pull out your own ensemble of layers. be creative, be innovative, and take a bit of a risk. while keeping it simple is easy and often chic, leave your comfort zone for a minute and try something new. think onion.