I saw this idea online and just had to try it. This lesson was a great way to teach sculpture and was easy enough for the little ones to do. We cut the top of brown paper bags in strips. (I told the kids to use their thumb as a guide to the width of each strip). We opened the bottom of the bag and twisted into a trunk. Then twisted the top strips into branches. I hot glued the trees to a small piece of cardboard to help them stand up and students tore paper leaves to glue to the branches.