Symetrical

http://fc00.deviantart.net/fs38/i/2009/106/2/1/Symmetrical_by_smartybarty.jpg

Asymmetrical
http://exper.3drecursions.com/apo/swirled_asymmetry.jpg

Radial

http://www.flickr.com/photos/moximus/4343502072/sizes/m/in/photostream/

Rule of Thirds or Golden Mean

http://wiki.ubc.ca/images/3/30/Landscape-Rule-of-Thirds.png