For this photo I sculpted the alien with epoxy clay, then I made the background with everything I could find that would pass as "spaceship" stuff (I used pencils, batteries, lids, etc). I painted the whole thing gray and silver.
for the floor I borrowed some griddles from the kitchen and I distributed them over a black piece of fabric so they would look rather convincing.
This is how the alien looked before the paint.
Camera: Canon 5DIII
Lens: Canon 50mm
Flash: 1 Lumopro LP160, 1 Cactus AF50 (which I don't recommend), And a Clairex
Flash trigger: Cactus v5