Avoid High Speeds - When driving on the motorway try and stick to 70mph. Avoiding high speeds on motorways and A-roads can save a lot of petrol. Around 50% of the power produced by the engine is used to overcome aerodynamic drag. Drag increases rapidly above 70mph so you fuel consumption will suffer.

Smooth Driving - Acceleration and deceleration is what uses most fuel. For this reason you will improve your fuel consumption with smooth driving, Also avoid heavy acceleration from the lights and try not to rev too much.

Don't Coast In Neutral - Modern cars automatically shut off fuel to the engine if you're not accelerating, but in neutral the engine will still use a tiny amount of petrol, so when cruising up to the lights keep the car in gear.

Close Your Window - If you are driving fast then don't have your windows open unless necessary. Having the windows open causes significant drag which increases fuel consumption.