When I was in the 5th, 6th, 7th, and 8th grades I had Mrs. Blasienz for a teacher. She would not let us throw away paper. From her I learned to be economical in my use of school supplies. I save or reuse almost everything.
We all get trash mail, and we want to immediately throw it in the waste basket. Those companies that want you to get a new credit card or try their service or product often send you a clean envelope so you can respond in it.
If the envelope is reusable, I put a small label on the printed address and reuse it myself. If not, I don't throw it away. I glue it shut and then after it dries I cut it into four pieces. The inside of the envelope is clean. I cut the envelope into four pieces. Voila, I now have four note sheets. I can use them to write my grocery lists on them or use them as reminders.
Whatever. Those small pieces of paper are useful; they are just for me and don't have to be beautiful with little colored flowers on the corners.
And just think...if you do this enough times, you might be helping to save a tree.