Use the "offset" sliders to move objects around.

Is there a way to move objects in smaller increments? Right now I hover my mouse over the sliders and use the scroll wheel to change them, but the step size is just to large sometimes. You can do more precise placement when you first place an object, but doing this in 3d is a real pain...

I hope they bring over the control scheme from the GalCiv 2 ship editor. I much rather liked being able to grab a "piece" and put it anywhere in the 3D box I wanted. The tile editor here could really use that kind of functionality.

The best I have found is select the slider and then use the arrow keys. Still not fine enough yet but we can hope it is moddable.