Tips on Fuel Saving

1. Pump petrol at night or in the early mornings. The temperature is cooler at these times so the molecules of the petrol are shrunk. This means you get slightly more petrol for the amount you are paying. If you really want to get everything, then lift up the hose so that ever single drop is not left in the hose.
2. Service you car regularly. A well maintained car means it is performing at its best. 
3. Be careful with your right leg.  This is both for the throttle and the brakes. Throttle on moderation as excessive throttling will obviously mean using more petrol. Avoid braking suddenly and braking often. As you car moves, the petrol and air mixture will change. After a certain amount of cruising, there will be more air in the mixture than petrol.  When you brake, this same amount won't be sufficient to keep the engine running, so the computers will change the mixture to more petrol to ensure the engine doesn't die. 
4. Check you tires often. Make sure there is enough air in them. As less air will make the car drag itself, which means the engine has to pump in more petrol to keep up with the demand. Also look into fuel economy tires. These tires have specially designed threads to have less resistance. Keep in mind for you drivers that want performance. These tires are not for you. 
5. Plan your routes. Knowing your routes well will help you save on fuel. Know which road will be more efficient for you with consideration of time and money. Some roads might be longer but remember cars use less petrol while cruising at a constant speed. Avoid getting stuck in jams as this is a major reason for fuel waste. 
6. Clean up your car. See those random things lying around in the car? Get rid of them if they are not essential. Might not seem like much, but these things might amount to a considerate weight.  The heavier the car is, the more the engine has to put out to cope with it. 
7. Use good car batteries. Find car batteries that takes less time to charge.  When the battery is charging, it is stressing out the engine which means again, more petrol use. Having a battery that requires less time charging means your engine won't be stressed.
8. Speed up before a hill or incline. Building up speed before going up a hill will save fuel. If you start throttling once you reach the bottom of the hill, again, more petrol use as the engine needs to cope up.
9. Wash and wax. Keeping the exterior of your car clean does help improve your fuel economy. Amazingly.
10. Use the highest gears if possible. Lower gears are set for performance while higher ones are set for economy. If you car is equipped with cruise control, this will be a gem to help you save up on fuel.
11. Aircond vs windows. Air conditioning uses stresses the engine. So think every time you switch it on. If you are driving at low speed or around town, its better to drive with the windows down. Once at highway speeds, just switch on the ac.
12. Avoid idling the car for too long. Cars consume on most cars a mixture ratio of 9:1 of petrol and air while idling. Its best to switch if off then restarting it again later.
13. Warm up the engine. Not only is this good for the lifespan of the engine, but it saves fuel as engines use up more fuel when its cold compared to when its warm.