I'll throw .02 at this too...I am no expert by any stretch of the imagination but I have found that the
aforementioned, changing of camera angle is a great way to create depth...

Here is one of my better images that gives the illusion of some depth > [ **Meeting...

**](http://www.renderosity.com/mod/gallery/index.php?image_id=1858217&member)Experimenting with the cameras angles and focal distances can create some pretty dynamic results, Just keep notes on the angles you find that work :)

Also, Consider adding Depth of Field, although it can be crippling to a lower end system, there is always the option of Postworking  "fake" DOF into your images.