When I'm writing, I tend to leave out a lot of environmental descriptions. This might be because I want the action to move along quickly. Excitement! Explosions! People flying through the air! No time to tell you what colour the walls are, we're DOIN' STUFF over here!
This might be because I trained myself on flash fiction. Whatever the cause, I need to consciously practice writing those descriptions that I otherwise leave out of my work. I'm not yet sure how to do this, but I'm trying something at the moment where I take something I've written before and just write another version that is all environment and description. No dialogue allowed, so I can't get expositiony, and no character names, either. I'm not sure if the "no names" policy will work well, but trying to tell the same story with nothing but environment and explicit facial expressions or gestures - no interpretation - is much trickier than I'd expected.
Mokalus of Borg
PS - I'm also not sure how to integrate it with the rest.
PPS - I guess that's a whole different struggle.