When it's time to discard your fresh Christmas tree after the holidays, be sure to give it a thorough inspection first. Make sure anything artificial -- string, tinsel, ribbon, ornament hooks -- is completely off the tree. Since most communities turn fresh trees into mulch, these plastic and metal bits and pieces can get shredded and inadvertently blended into the organic mixture. These small bits of trash can end up washing into creeks, then rivers, and eventually into lakes and oceans, where they cause pollution. If you want to take an even bigger step, avoid putting anything plastic on the tree to begin with. Decorate with natural materials and keepsake ornaments you know will never have a chance of accidentally being left on the tree come Dec. 26.

Many people use firewood as a source of heat during the winter months. While it may seem like a time-saving idea to stack large amounts of wood inside the home, it's best to bring in wood on an as-needed basis. When you bring in firewood, you risk introducing mold spores into your home, which can affect your indoor air quality. For people who have asthma and other respiratory illnesses, this can be a health problem. Most people want to avoid a mold infestation in their home anyway. Instead, store firewood outside in a dry place, like the front porch, and bring it in when needed.

Here's a simple habit to get into with your garage door at home: Keep it closed. When your garage is warmer in the winter and cooler in the summer, you'll save on your overall energy costs. Since the garage is often connected to the house, cool air that blows in from outside during the winter can make its way into your home, and vice versa during the summer. So consider using the garage door to get your car inside and outside only, not as another door to and from the house.