For us, the less thinking and less work involved in saving that money, the better. These are just a few of the passive saving tactics that have helped us cut our budget and continually save money (and also happen to be pretty eco-friendly.) Most of them you only have to perform once, with a time investment of anywhere from 5 minutes to an afternoon.
1. We installed a programmable thermostat...and actually SET IT! Programmable thermostats are a great thing because they allow you to have the best of both worlds--lower/raise the temp while you're away to save energy and money, while still being comfortable while you're home. Pick one that will suit your family's needs and schedule--you can even set totally different schedules for every day of the week if your thermostat has that capability. But, you have to take the time to set your desired schedule and temperatures and use the programmed settings!
Obviously there is an upfront cost for the thermostat itself. Comparison shop online at sites like Shopzilla or Pricegrabber and be reasonable about the features you need and will use so you're not spending more than necessary. Prices start around $20 for a basic model and go up to $150 and above for a high end touch screen version.