Retro Sci-Fi Tutorial

Do you ever wanted to paint a sexy/retro space chic? or, do you ever wanted to do some ugly Martians like taken from classic sci-fi movies?... or, do you want know the secrets behind some of my most popular retro illustrations?... well my friends, look no further, here are all those answers
I made a very detailed step by step tutorial of this illustration, from the basic pencils to exactly this final image you see above.
And where do you get this?: in the next issue (nº36) of the awesome 'Digital Artist Magazine' from Imagine Publishing, UK [link]
Hope you like it.