Tips for getting better 3D rendering

Ok so i'm not really a 3D artist, However i needed a few tips as to lighting and rendering to make my 3D City look sort of real, somewhat close to the rendering done in 3ds Max. I've been tweaking the Unity graphics quality options for over a week now but i don't think i'm getting close. I have no performance limitations as the Project is a PC standalone and is expected to run on a high powered GPU. Can someone point me in the right direction?
I'm using Unity Pro.
I have a deadline in 13 days...

Tips for getting better 3D rendering