Since I received a couple of requests for a small texturing tutorial and I had a bit of time at my hands, here is a small, hopefully helpful, example...
This is the example of how I textured my TMP-Enterprise, focusing on a part of the top saucer.
First is of course the UV layout. The top saucer including the rim is split in two texture sets, each 4096x4096. The whole ship has about 7 of these sheets, plus all the registry and decals. Of course not every ship needs this large amount of textures, but I love to get pretty close to my ships and hate it when textures get blurry.
You can see that I did not just map the saucer from the top, but rather cylindrical (in fact, it is done with a spherical projection). This way, you get sharper textures, no jaggies on the small panel lines and the aztec pattern.
Also, you get a bit more texture space for the elements. The downside is that itAâ€™s not that easy to get battle damage and such stuff on a specific point on the texture. I usually use transparent extra geometry/textures for that, like the NCC registry.
IAâ€™ve coloured some example areas. The lighter areas are the same as the darker areas, they get reused.
Once this is done and all nicely layed out, the next step prior to actual texturing is baking out an ambient occlusion pass. For one, this provides a nice guideline when texturing - plus I tend to mix the ambient occlusion part to a certain degree (about 30-40%) into the color pass.
EDIT: The uploader swapped the pics, so the first pic is always on the right, the second to the left. Just to avoid confusion when reading the text...