Location, location, location.
Think about the features of the city - industry, architecture, culture - and try to throw in an event (even if it's a fight) that highlights one of these. That'll make the city (and the fight within it) memorable to your players.
For example, if you were in a modern setting (James Bond or Bourne, let's say), and some of the action took place in Venice...well, that just demands a gondola chase, doesn't it? Think back to "every movie you ever saw" that had scenes in a foreign city, and how that foreignness was highlighted.
PCs go to Mexico? Obviously, it happens to be a fiesta, with shooting in the air, fireworks, people dancing in the streets. At some point, there will be a burro.
PCs go to Hong Kong? Obviously, it happens to be Chinese New Year, with acrobats and a bunch of guys in a dragon costume.
PCs go to Pamplona? Must be running of the bulls. That courier has what you came for, and he's getting away...down the hill, and here come the bulls...
PCs go to London? Rooftop chase with chimney sweeps. Something involving a double-decker bus. A combat on the face of Big Ben's clock, with someone hanging desperately from the minute hand.
The Alps? Ski chase is mandatory (cello case is optional). Paris? We're not leaving til someone has to climb the Eiffel Tower. Can't do Monte Carlo or Vegas without a gambling scene in a casino, right?
It's all about scoping a location and highlighting the cool bits. You can't have a fight on a pirate ship without said fight moving up into the rigging, can you? Of course not! And why would you want to? Use the tropes. Even a feature which at first doesn't seem pulpy or exciting can be turned up to eleven. If the PCs are in upstate New York, and you look at your guidebook and all it says is "major production center for pencils", wow, maybe that sounds lame. But what about a fight in a pencil factory? With buzzsaws blazing, precariously-stacked boxes to climb on, and spilled pencils everywhere (good luck keeping your footing)?
Recall in 'Pirates of the Caribbean' (the first one) the fight in the blacksmith's shop. It's as though the writers sat down and said "okay, what cool stuff is in a smithy that we can highlight in the swordfight?" You should be doing it, too.
You can do the same thing with your fantasy cities - come up with a couple of 'gimmicks' to help flesh out what's different about each one, and make sure your players see those gimmicks when they first visit the town. It'll be a kind of foreshadowing. When PCs go to City X and you describe how City X is famous for having the world's largest hedge maze, the players should nod to themselves and say "hedge maze...that's gonna be awesome", knowing full well as some point they're going to have to chase someone through that darned maze. Once the pattern is established a little, you might be surprised to see your players steering things in a way that's actually to their disadvantage, just so that they can "use" the local feature.