This video from the National Park Service is an excellent summary of the Seven Ethical Principles of Leave No Trace.

  1. Plan Ahead and Prepare
  2. Travel and Camp on Durable Surfaces
  3. Dispose of Waste Properly
  4. Leave What You Find
  5. Minimize Campfire Impacts
  6. Respect Wildlife
  7. Be Considerate of Others

Downloadable versions of the video with additional features are available at

http://www.nps.gov/features/wilderness/leavenotrace/popup.html