What can I do to improve the fuel efficiency of my Vauxhall Astra?

I have noticed that my Vauxhall Astra is not getting as many miles per gallon as it used to. What are some steps I can take to improve its fuel efficiency?

Regularly maintain your car, such as getting regular oil changes, tire rotations, and air filter replacements.

Avoid idling for long periods of time and try to combine errands to minimize trips.

Check your tire pressure regularly and make sure they are properly inflated.

Consider using a fuel additive to clean your engine and improve fuel efficiency.

Drive smoothly and avoid sudden accelerations or hard braking.

Remove excess weight from your car, such as unnecessary items in the trunk.