If you're a frequent flier, one of the easiest ways to cut down on one small wasteful act is to opt for a mobile boarding pass instead of a printed one. Over 1.5 billion boarding passes are issued every year, which adds up to a significant amount of paper (often coated with the chemical BPA) being used and almost immediately thrown away. Airlines are making it easy: Apps for your smartphone let you download passes, save them and do a whole host of other things to make your flight manageable.

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.