How can I optimize my Kia Ceed's fuel efficiency?

I've noticed that my Kia Ceed is consuming more fuel than usual. What steps can I take to improve its fuel efficiency?

Regularly check and replace air filter and spark plugs for improved engine performance and fuel efficiency.

Avoid aggressive driving and maintain a steady speed to reduce fuel consumption.

Ensure that tire pressure is maintained as under-inflated tires can lead to higher fuel consumption.

Use a fuel additive to clean the fuel injectors and improve fuel economy.