shaded relief to top down city map

[mwsasser]

Do you fellows know a good technique to add shaded relief to a top down view city map? I have some b&w maps drawn in photoshop and the like that are on a cliff next to the sea. I just wanted to add a shaded relief style cliff or add some terrain to the area around the city. I've also considered making part of the city on a higher bluff than other sections. Any idea how I'd do that?

Here is the sample style of map I am referring to.