Use an Aperture That Takes It All In

When you're shooting in a city, unless you're shooting an object close up (where you intentionally want the background out of focus), chances are you want as much of the city in focus as possible, right? That's why an f-stop like f/11 works great in a city. It keeps pretty much everything in focus, as long as you don't set your focus on the closest thing in the framethe rule of thumb is to focus on something about 1/3 of the way into the scene you're trying to capture.