How do I troubleshoot low fuel economy on my Audi A6?

My Audi A6 has been getting lower than expected fuel economy, and I'm not sure why. I've been keeping up with regular maintenance and driving conservatively, but it doesn't seem to improve. How can I troubleshoot and improve my fuel economy?

Check your tire pressure and ensure they are properly inflated, under-inflated tires can decrease fuel efficiency. Additionally, make sure your air filters are clean and replace them if necessary.