If you're using multiple views (isometric as well as orthographic), I find that zooming in considerably in the top, left or front view and dragging there, as opposed to using the omnidirectional move tool in the perspective view allows for much finer movement.  Zooming in on the view in the perspective window can get a little confusing when you go to dolly the camera around, so I just keep it wide enough to see the entire production frame and zoom in the isometric views.

 - Dex