Offer someone a lift home, or elsewhere if they need help with transport.
Be a safe driver, don't distract yourself by texting while driving, or anything else. Focus entirely on your driving.
If you pre-pay for parking but end up not using the full time slot, pass the ticket onto someone else who can.
Instead of driving, find a different way to travel to work to be both environmentally friendly and even possibly better for your health - walking, cycling, public transport or car sharing.
If you are waiting for a taxi and can see someone is clearly in a rush, let them take the first taxi, or share it if both going in the same direction.
When parallel parking leave a reasonable gap between the cars infront and behind you. Also pay attention to vehicles with disabled access markings and the extra space they need.