Rule number one: Anticipate your driving!
Try to keep your eyes far enough and analyze the traffic all the time. If you see a light going red or brake lights lid 10 seconds ahead of you, start coasting, and try to aim for the maximum possible speed when you can start accelerating again.
Accelerate at least on half throttle, and jump gears if possible. Revving on 3rd to cruise speed and then changing to 5th is more efficient than going 3 -> 4 -> 5.
On highway or A-road lift a bit on downhills and gather more speed BEFORE an uphill, so you don't have to give more gas at the hill (=more load, bigger consumpion).