For creative urban landscape photos, think about the angle you’re shooting from - buildings are not all uniform so you surely aren’t going to shoot them all from the same perspective. For example, if the building is really tall, squat down as low to the ground as you can get, and shoot upwards - you’ll get more of the building in your frame, and it will really emphasize its size. If the building has a dome, put something with a different shape in the foreground that shows off its rather nice shape. For example, you can take a photograph of a small rectangular building in the right-hand corner of the photograph with the dome building in the background. If you can, get a straight object next to it. That may mean dragging your friend away from the vending machine and putting him at either the right or left corner of the shot.
Find the Hidden Jewels
While you may be told over and over again to not sweat the small stuff, in this case DO! You want to find the small details that other photographers may have missed. This is doubly true for any building that is found in nearly every travel website, catalog and photography book (ahem, the Empire State Building, the Chrysler Building, Globe Theater ... you get the picture). For example, focus on the columns near the entrance or even a few of the windows that line the entire building.
Walk around the entire length of the building. See if you can get access to places behind fences or gates since a lot of photographers won’t be going the extra mile to find the nooks and crannies the typical tourist won’t see. Since you may have to get permission to photograph certain buildings anyway, you can go ahead and ask for access at that time.