-All maintenance should be done regularly like airfilter, oil, oil filter, spark plugs etc.
-Keep light foot while driving.
-Keep revs as low as u can.
-Change gears at appropriate intervals (if auto, try to shift at early as possible by keeping low on throttle paddle). Avoid unnecessary harsh braking. Avoid sudden turns.
-Try to keep windows rolled up as much as possible. Don't overload the car with luggage and people.
-Keep the tyres properly inflated.
-Run AC on as low step as possible. It will also cool better due to repeated tripping cycles
-Get the brakes checked if they are touching the disks all the time.
-Instead of several small refills, refill the tank completely.
As much as i can remember for now