What's the best way to maintain my Nissan X-Trail's fuel efficiency?

I recently purchased a Nissan X-Trail and I noticed that my fuel efficiency has decreased. How can I improve it and maintain it in the long run?

Regularly check and change your air filter to improve engine performance and fuel efficiency.

Avoid excessive idling and aggressive driving, as these can greatly impact your fuel efficiency.

Make sure your tires are properly inflated to reduce fuel consumption.