How can I increase the fuel efficiency of my Vauxhall Astra?

I recently purchased a Vauxhall Astra and I noticed that I am spending a lot on fuel. Is there anything I can do to improve its fuel efficiency?

Regularly check and replace air filters to ensure proper air flow. This can improve fuel efficiency by up to 10%. Also, ensure your tires are properly inflated and consider using low rolling resistance tires.

Take it easy on the accelerator and avoid quick starts and stops. This can improve fuel efficiency by up to 20%. Also, try to maintain a constant speed while driving on the highway.

Consider using a fuel injector cleaner to remove any build-up in your engine. This can improve fuel efficiency by up to 25%. Also, avoid idling for extended periods of time.