At the Office
Print Prudently: Always ask yourself, "Do I really need to print now?" If so, make sure you retrieve your paperwork right away, so you don't fall prey to the out-of-sight-out-of-mind reprinting cycle. Also tighten your margins and use both sides of the page whenever possible. And be sure to recycle your printer cartridges. Most major office-supply stores accept them now.
Sip Smarter: Bring your own coffee mug instead of relying on the disposable variety in the break room. By purchasing a cup of coffee in a throw-away cup every day, you create about 23 pounds of waste each year.
Green-Bag It: Pack your lunch in reusable containers. If you can't break away from baggies, try Mobi's reusable, biodegradable ones with vegetable-dyed prints from designer Todd Oldham ($5 for 20 sandwich bags; mobi-usa.com). A portion of the proceeds from the bags goes to the NRDC.
On the Road
Avoid Idling: If you need to warm up your car engine on a cold winter day, try to limit idling time to less than 30 seconds to keep your fuel emissions low.
"Dry Wash" Your Car: Though the bucket and sponge method may require less water than the local car wash, it may also be as environmentally unfriendly, introducing toxins into the ground-water that winds up in our drinking supply. Instead buy a waterless plant-based cleaner like Dri Wash Envy ($38; driwash.com).
More: Tips From Hard Core Commuters
Pack It Up: Stashing sample-size bottles of your health and beauty products in your carry-on is one way to comply with the TSA's liquid limits, but it's better for the earth-and your wallet-to snag a set of reusable containers.
Travel by Train: Planes produce 19 times as much pollution as trains do. When you do fly, offset your carbon emissions by going to terrapass.com and purchasing "credits" to fund clean energy projects, like those using wind and farm power. For more eco-solutions, check out idealbite.com, a Web site that delivers free green-living tips to your e-mail in-box every day.
More: Tips for Your First Bike Commute
Find an eco-friendly activity.