How do I properly maintain my Audi A3's tire pressure?

I've noticed that my Audi A3's tire pressure seems to fluctuate more frequently than other cars I've owned. What is the best way to ensure my tires are always at the proper pressure to maintain optimal performance and safety?

First and foremost, it is important to regularly check your tire pressure using a high-quality tire pressure gauge. This should be done at least once a month, or more frequently if you are going on a long road trip.