How to get better fuel economy from your 2012 Audi A8 4.2 Quattro?

I've owned my 2012 Audi A8 4.2 Quattro for a few years now and I'm interested in maximizing its fuel efficiency. The car is quite powerful, but I'd like to know if there are any tweaks or driving habits that can help me get better mileage without compromising performance or comfort.