http://starbrightillustrations.com/blog/2009/07/28/3d-spaceship-stage-by-stage-blender-tutorial/
I was watching a TV show about the strange creatures that live on reefs and I was inspired to create a nice blue spaceship that has the shape of a manta ray. A workhorse spaceship of the kind that’s so useful in sci fi RPGs. The screen shot to the left is the first stage where I have added a mirror effect to a starting half cube and have started to extend and subdivide faces into a rough impression of the 3D spaceships basic shape. I’ve also added the two major colours of the spaceship while the design is still simple and this is still relatively easy – I only had to select about seven faces of this simple mesh to colour this huge are of 
the spaceship hull. I’m really enjoying doing this sort thing in Blender, I’m still amazed that this great professional-level 3D modeling software is open source and free.
For the next step I decided to add some basic cubes to the blend and simply move them to the 3D mesh of the spaceship. The spaceship is going to be for an illustration so I don’t think I’ll bother to integrate these details to the mesh. Then I just change the colour of the cube to match the hull of the spaceship mesh and deform it until it 
looks like a surface detail rather than a strange grey cube sticking out.
Here I’ve flattened the cube and turned it blue so that it looks like a kind of spaceship ramscoop or gas intake of some sort or other.
This is all just the first step of course, pretty soon this spaceship illustration will be done and there will be some generic details to make it easier to use in role-playing games.
