Stop leaving the water on while brushing your teeth. This is a terrible way to waste water. Water is the most important commodity of the modern world. Lets treat it with respect.
After using the restroom, dry your hands with only one paper towel. We use the restroom multiple times on a daily basis. Let's make sure we're not using too many paper towels. There is no reason to use more than what is required.
Please refrain from throwing food away. Eat what you have bought. There are millions that go hungry, daily. The United States wastes tons of food each year. Let's do our best to reduce that amount.