How to maintain the fuel efficiency in an Audi A6?

I have recently bought an Audi A6 and I am wondering what steps I can take to ensure that my car's fuel efficiency stays optimal. My daily commute involves both city and highway driving, so any advice on how I can decrease my fuel consumption would be greatly appreciated.

First and foremost, make sure to keep your tires properly inflated. Under-inflated tires can increase fuel consumption by up to 3%.

Avoid idling for extended periods of time. If you know that you will be stationary for more than a minute, turn off your engine.

Regularly servicing your car and tuning up the engine can greatly improve fuel efficiency.