How can I improve the overall fuel efficiency of my Vauxhall Astra?

I have noticed that my Vauxhall Astra is not achieving the advertised fuel efficiency. What steps can I take to improve the overall fuel efficiency of my car?

Regularly service your car and replace any faulty or worn out parts.

Avoid idling for extended periods of time and make sure to turn off the engine when parked.

Consider using a fuel additive to improve fuel efficiency.

Ensure that your tires are properly inflated.