nxGangrel

Ya I just look at other peoples maps then make a map with the general idea but with my own twists.

You've been doing so much already, I dont think it would hurt to take a break and try playing through an old megawad you like again, or maybe try looking at cool art or listening to a new band and see if that inspires you.

As far as rectangles go, there's plenty room for innovation in terms of lighting and height variation. But if you don't feel you're putting out your best work, try reviewing some maps from the /idgames archive, make note of the things you like and try to incorporate them in your future designs :)

As these guys said...check out other maps for inspiration.  Hell, Doom 2 Redux was originally meant to just be a solo mapping exercise for me.  Ended up being a cool group project, made me a better mapper.