When shopping for holiday gifts online, opt to have the packages sent to your office or place of work instead of your home. If you don't normally have packages sent to your house, it means delivery services like FedEx and UPS have to make an unscheduled stop to bring the items to your house. That means more fuel and more greenhouse emissions into the atmosphere. By having the items shipped to your place of work -- which already gets daily visits from these carriers -- you reduce the wasted fuel by removing the additional stop. To be even greener? Opt for ground service instead of overnight. It's cheaper, and it uses fuel-efficient trucks instead of planes.