With smart projections, we have a quick way to work with UV textures. This tool allows us to do all the processing with only a few mouse clicks. If we want to take full control over the process, however, we will have to use special controls to change the UV mapping layout. To unwrap using those tools, we have to plan the unwrap creation before anything else.
For a good unwrap, we must first create groups of vertices that will be unfolded together in the process. As the unwrapping will end up with a flat model, we can split the spacecraft in small parts, which will be marked by seams. These seams work like a knife that cuts the model and creates a flat model separated by marks. Keep the following two tips in mind when cutting the model with seams:
Group the faces in similar textures
Make the unwrapped surface easy to edit in GIMP or Photoshop by identifying each part
A great way to start is by creating a test cut by adding a new UV layout. In Blender...