Public officials—elected and appointed—are there to serve their constituents (you). But they can only serve effectively when they know what we care about and need. That's why it's a good habit to contact them on a regular basis and discuss the issues you find important or share your views on current events, their work, legislation, policy, and more.
Unfortunately, too few people take the opportunity to engage policy makers. Most simply don't know how. But engaging our public servants is actually quite easy—especially with the help of today's technology.
One of my favorite tools in the world is Resistbot, which allows you to contact your representatives (and do a lot more) as easily as sending a text message. You can also quickly turn your letters into petitions for others to sign and send to their own reps.
Outside of that, you can find your federal representatives here:
Below are some of the letters I've written to my own representatives. Feel free to copy and share them, or use them as a starting point for your own words.