Bunker (Hi-Poly Hard Surface Study)

I've been reading up a lot about hard surface modeling in Maya, and finally think I have a firm enough grasp to attempt something small. I've done a low-poly block out, and now I am going to insert the loops I need so I can hold the edges when I apply the smooth preview (Maya 2014). I know its not much right now but any advice going forward or critiques are welcomed.

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