As an example, here's one of my uvmaps. A very different approach, but it demonstrates some things:
Note that there is some space very obviously wasted here. That's perfectly all right, though, because I simply didn't need it for anything- the only things I was going to be able to fit into that texture space were things that, quite frankly, were scaled large enough for the details I wanted to put on them.
This was one of the earlier models I did for NanoBlobs, and quite frankly, it shows in a number of areas, however. In my hurry to get things done, I did a pretty poor job of mirroring my objects, and other little things- however, you really cannot tell in the final results very well:
If you look carefully, you can see how I very deliberately played with the relative scales of things on this model, emphasizing some areas, and not others, in order to conserve texture space and make sure I had plenty of room for essential details. As my style is much less clean than Smoth's, I use dirty noise whenever possible to help confuse viewers about the level of detail they're seeing and to increase the feeling of raw detail on my models whenever possible, along with carefully painted greebles and other fine detail. A few really nice gizmos, in a carefully-picked spot on a model, makes a huge difference.