Tip #1: Be bright about light
Artificial lighting accounts for nearly half of the electricity use in office buildings, so make sure that lights are turned off whenever no one's in a room — and invite in natural light wherever possible. Make it a policy, too, to buy Energy Star-rated lightbulbs and fixtures, which use at least two-thirds less energy than regular lighting, and install timers or motion sensors that automatically shut off lights when they're not needed.
Tip #2: Shut down that PC.
Tip #3: Print smarter.
Tip #4: Rethink office lunches.
Tell us: How do you green your workplace?