Instead of buying plastic water bottles, buy a reusable bottle and fill it using your home filter.
Let the shoes stay at the door. This way you will not bringing bacteria and debris from all over the place into your homes which in turn gets stuck in the carpet making it a germ breeding ground.
Invest in-house plants. They help absorb carbon dioxide and other toxins and give off fresh oxygen instead.
Whenever possible, go paperless.
Opt out of junk mail.
Put the laptops in “Sleep” mode when not in use. This will help conserve energy.