Well, vanishing points are, together with the horizon, the basic starting points for every drawing that uses perspective. Have a look at this video (the instructor sounds likes he's teaching a four year old but just ignore his tone) it's the most basic explanation I could find. http://youtu.be/4tv06f--1wI?t=51s I hope it…
Something else to keep in mind with Giger is that his art tends to be noisy. Part of the visual direction for UT is that we'd like cleaner, more readable visuals that allow characters to stand out from the background a little more. So maybe shoot for a Giger inspired design, but with less clutter... Your current drawing…