Generally a story has more than one setting which places the burden on the writer to bring each place alive. One way you can do that is to plan a walkabout with camera or notebook in hand.
You might want to focus on architecture, such as the shapes of buildings, bridges, and archways. Cities generally have a mix of architectural styles since they are developed over periods of time. Downtowns are frequently the oldest part of town. What features do you see there? In San Francisco, you would see a lot of stucco facings and large, carved wooden doors. Around the doors and windows might be whirliques, demons, saints and sinners alike. If you can, walk inside and describe what you see. Marble staircases and floors? Gilded handrails? Wood flashings and trim?
If the buildings have been remodeled or replaced, massive steel and glass structures might have arisen. Step inside, keeping in mind the contrast to the old buildings that used to be there.
Cross over a bridge or two. San Francisco has two important bridges, the Golden Gate and the Bay Bridge. The first is an orange structure that connects SF to the Marin side. It traverses what would be a huge cavern if not for the bay waters far below. When you look at it, think about what stories it tells. There have been many jumpers, almost all of whom died. What would bring someone to jump off that bridge? Think of the car accidents that have taken lives. What were the drivers doing when they crossed over the separating lines.
The Bay Bridge is a modern structure with massive steel cables. It is beautiful, but is shrouded in controversy. The cost to build it went way beyond projections. Think of the story to be told about the negotiations that might have taken place. There are bolts that are rusting, causing some to fear driving over the bridge. Not that we want that to happen, but think of the fictional piece that could tell that story.
As you walk up and down the streets, look at the doors. I’m willing to bet that no two are alike. Note the colors. Do they signify anything or did the owner choose by random? Imagine the story if color meant something. Green for an herbalist, yellow for an apothecary. Red for law. Blue for police. What stories come to mind?
If you don’t have time for a walkabout, go on an imaginary one in the setting of your story. Take notes. Make lists. Come up with potential conflicts and events.
Your task is to write a scene in which the environment is crucial to the story. Don’t spend copious amounts of time describing the scene, but allow the elements to slowly come into play.
Have fun with this one.