If your car is parked and idling for more than 10 seconds, turn it off. Even though you're not driving at highway speeds, a car that's on but not moving is still using one-quarter to one-half a gallon of gasoline per hour. In the colder winter months, if you want to warm up your car, it's recommended you do it for no more than 30 seconds total. With new models, that's not even necessary; it's driving that actually warms up the engine, not simply turning it on.

A timeless tip but a good one: Always bring reusable bags to the grocery store. According to EarthShare, if you grocery shop once a week, in five years' time, you'll have prevented anywhere from 250 to 1,000 grocery bags from getting into the landfills. But why only bring reusable bags to the grocery store? Use them at the hardware store, when you shop for clothes or at any store where you can opt out of using a bag. And if you forget, ask if the store can put your items in a cardboard box -- there are usually lots in the back -- and put it in the recycling bin as soon as you get home.

It's a well-known fact that houseplants are some of the best things to keep inside your home to purify the air. But having houseplants in every room of the house can be a little too much. Here's the good news: According to NASA, indoor plants absorb pollutants through their leaves and roots and make fresh air from it. In just 24 hours, they can remove 87 percent of the toxins in a room. So by moving houseplants room-to-room day by day, you can help purify the air throughout the whole house. Be sure they are placed in a sunny spot so they can thrive as you move them.