What is the best way to improve the fuel efficiency of my Vauxhall Astra?

I've noticed that my Vauxhall Astra doesn't seem to get as good gas mileage as it used to. Is there any maintenance or driving habits I can implement to improve its fuel efficiency?

Regularly check and replace your air filter to improve air flow to the engine. This will help it burn fuel more efficiently. Also, make sure your tires are properly inflated to reduce rolling resistance.

Avoid unnecessary idling and accelerate slowly. Rapid acceleration and constant stop-and-go driving can greatly decrease your car's fuel efficiency. Also, try to combine errands and plan your routes to minimize time spent in traffic.

Consider using a fuel injector cleaner or getting a professional fuel system cleaning. This can help remove any build up in the fuel system that may be affecting its efficiency. Also, make sure to use the recommended grade of gasoline for your Vauxhall Astra.