Okej, so I have sketched kinda random with a custom brush. I am so far not done completely with the rough part yet.
If you can squint your eyes you can see they looks like ship, thats what I wanted now it is time to refine the details by using a default brush with opacity 50-70%
Oh and btw I forgot to explain they are not any ships, they are built by garbage just like the movie from district9. You get the idea.