Look for Bold, Vivid Colors
One of the things to keep an eye out for when you're shooting urban and travel shots are the bold, vivid colors of the city. You'll often find brilliantly colored walls, doors, (shots with a bold-color wall with a contrasting colored door), shops, signs, cars, and bikes. One of my favorite urban shots was of a bright red Vespa scooter parked directly behind a bright yellow Lotus sports car. It almost looked set up for me, and I took dozens of shots of it because the colors were just so vivid, and so perfectly matched. Keep your eyes peeled for brightly painted walls (especially wonderful if you find someone working in front of the wall, or waiting patiently for a bus with the colorful wall in the background, or a bright yellow car parked in front of a bright blue wall). If you're looking for these colorful combinations while you're out exploring, you'll be surprised at how often they'll reveal themselves to you. By the way, I know I'm beating a dead horse here, but these colors will look richer and have more depth in (you guessed it) great light, which generally occurs (you know it) around dawn and dusk. Just remember, the next best thing to those two is open shade.