Is it more fuel-efficient to drive with your car windows down or with them up and the air conditioner on? Turns out, if you're on the highway going more than 55 mph, driving with your windows up is a much more fuel-efficient way to go. At high speeds, open windows create drag, which can reduce your car's efficiency as much as 20 percent. But at low speeds, when you're driving around town on surface roads, it's better to crack a window and leave the air conditioner off. There is less drag, and your car is producing less energy to operate, so feeling the cool breeze through the window is the greenest way to go then.

If you have a backyard pool, one easy habit to get into is to make sure it is covered whenever it's not in use. In just one week, a pool can lose about an inch of water if left uncovered. By simply covering it, you can help save as much as 95 percent of that evaporation. Covers also help conserve heat, which is another cost of owning a backyard pool; help keep the pool cleaner, since leaves and other debris are kept out; and it's safer.

In the summer months, it's imperative to take simple steps in your outdoor garden to help conserve water. The biggest step you can take is to make sure the soil for your landscaping is properly conditioned. If there is too much clay in the soil, it can keep water from being absorbed, which will cause plants to wilt. Conditioning the soil with organic matter like compost and sand aerates the soil and allows you to water less and get better results. Add a few inches of mulch on top of the soil to help prevent evaporation.