As an avid photo-editor, I have a few gimp and Photoshop tutorials on one of my blogs called Gimped! (http://www.gimpedtutorials.com) One day it hit me - no matter how many we come up with as a community, some people will still struggle understanding some of the theories behind what we do in our Gimp Tutorials. In light of this, I wrote a free article called "Principles of Photo Editing" which teaches people my 5 greatest tips that will make you a better Gimp user, and clearly spell out the theories that a lot of people misunderstand when viewing tutorials online.