Above this sentence is an amazing letter written by a 14 year old. I would make today's tip to be more like Sophie but, I don't think anyone could say it better (or even close).
#11 When printing something use both sides of the paper. This is easy to do. Use a test page and figure out which way to insert the paper so it prints on the back. And I know I have said this before but, enviromentally friendly tasks like this are economical. In addition, once I did this and my teacher congratulated me on being "earth smart". So, there you have it. Three good reasons to do something great.