The first easiest way to keep the heat turned down but not freeze is super-obvious and easy: layer some clothing! Make sure you have nice warm socks or slippers on your feet, and pull on a comfy sweater or hoodie. Yes, it is that easy! Before you touch the thermostat, take stock of what you have on and decide if maybe you can't skip the energy bill and bundle up a little. Now, I'm not suggesting you look like the Michelin Man and lose the ability to move your arms or fall over and can't get up like "A Christmas Story", but be reasonable. if you're cold and you have on a t-shirt... well... c'mon.
Another easy way to warm the home and hearth a little: bake! This is a really good way to warm things up without cranking the heat. It helps for a few hours, anyway. And who doesn't love cookies or pies or nice hot yummy casseroles? Banana bread? Pumpkin bread? You'll be the hit of the office or the neighborhood if you gift these things you lovingly baked. You can prepare meals or soups for the coming week, thus being greener with your cooking and better with your time and money... no take-out all week. No use of plastic forks and Styrofoam and take-out plastics. (See how many ways you save by the littlest of actions? It really is a domino effect.) And get the kids involved with the cookies. It's great family time that they will treasure all their lives, and it gets them off the computer or gaming systems for a time, thus saving MORE energy on the electric bill.
It's the little things. A lot of good stuff snowballs when you do green things. So get out there and do it!