How to increase fuel efficiency in a Vauxhall Insignia?

I recently purchased a Vauxhall Insignia and have been struggling with high fuel consumption. Are there any tips or tricks that can help me increase the fuel efficiency of my car?

Regularly check and replace air filters to improve air flow and reduce fuel consumption.

Avoid idling for long periods of time and use cruise control on highways to maintain a consistent speed.

Check your tire pressure regularly as under-inflated tires can decrease fuel efficiency.