Almost every daily newspaper publishes letters to the editor. Many people read them. With a single letter, you can draw widespread attention to your concerns and perhaps get more support. If your letter is published, show it to other people. Photocopy it and include it with handouts, fliers, news releases, etc.
Follow the paper's instructions. You can find them in the letters' section, near the editorials. They will tell you where to send the letter and other requirements.
Type and doublespace the letter.
Include your name, address, and daytime phone number. Many papers contact the sender before publishing the letter.
Use "To the Editor" as the salutation.
Keep it less than one page. Long letters are seldom printed. Editors shorten longer letters.
Focus on one issue only.
Get to the point. Say why you're writing. State your opinion and the reasons that support it. If you have a solution, include it as a suggestion.
Make it stand out. Your letter will have a greater chance of being published. What makes a letter stand out? It might be interesting, have a good argument, use language well, be funny, etc. Include your age if this will help your letter stand out.