For many people, a large part of their direct emissions are created by using their car. One of the most common uses of a person's car is to get to work. By using public transportation, carpooling, biking or walking instead of your car you can make enormous reductions in the amount of emissions you cause everyday.
If these methods of transportation are not an option then try changing your driving habits. Even if you have purchased a small car, when you drive at speeds over 95 km/h you greatly reduce your cars advertised fuel efficiency. Apart from this, sharp accelerations and idling also reduce fuel efficiency. That's why avoiding rush hour and driving all together if possible is a great way to reduce emissions.