One of the easiest ways to give your old toilet a water-efficient upgrade is to divert the amount of water the tank holds and uses per flush. An old trick (that you should not do) was placing a brick in the tank; it filled up space and forced the toilet to flush with less water. The problem with using a brick is that it's made from baked clay; over time, water breaks down the brick, and particles and other sediment clog the plumbing. If you can't replace your old toilet with a new water-efficient one, fill a plastic tub with pebbles and seal it with a tight-fitting lid. Then place it inside the tank. You'll save around 2 to 3 gallons of water with each flush.

Glue-covered sticky traps are commonly used by pest control companies to capture mice. But it's also incredibly inhumane, since the mice often starve to death or chew off their own feet in an attempt to free themselves. While we don't advocate glue traps at Do Just One Thing, there is something you can do if you find a mouse stuck on one. All you need is a paintbrush and vegetable oil to free them. Pour a liberal amount of oil over the sticky part and use the paintbrush to nudge the mouse off the trap. Be sure to do this outdoors, where the mouse can recover in a warm area after you free it.

Whenever you fill your car with gasoline, always fill it all the way up. By doing so, you'll make fewer trips to the gas station and increase the fuel efficiency of your car. Also, when the pump clicks off automatically when your car's tank is full, don't remove the pump right away. There is about one-fourth cup of gasoline still in the hose line (that you paid for) that needs to work its way into your gas tank. If you wait about 15 seconds, you'll get every last drop.