Portal 3Dworldmag published a quick tutorial about using the symmetry or mirror function in 3DsMax and so rapidly cutting your time by UV mapping. The tutorial is explained on an organic mesh and 3DsMax; however you can apply this technique on most of 3D Applications. The guide begins by deleting the half of the model and applying mirror to the mesh, like this you will achieve that any change on one side will be mirrored to the other side.
It continues by describing the applying of UV map to your model and using modifiers to tweak your final result. This short guide looks very interesting because it’s a nice trick how to save a lot of time.
Source and full guide: 3DWorldmag