When ever I am making maps, I always come across the same problem, and this problem is usually the problem that makes my maps go from amazing to blah. I never know how to fill in the map after I put down the first two bases. Lately I've been experimenting with maps that don't have bases but it still doesn't help. I don't know how to lay down cover, or how to fill in the large empty spaces in maps. Anybody able to help me?
I think what would help is to take a look at the multi player maps in their default form;ex: Narrows, Last Resort, The Pit... Play on them for a while and see what makes them fluid, fun maps. Pay attention to the structures and how they effect game play. maybe even look at levels in other game besides Halo! Most shooters have somewhat similar level design and could help inspire you with your levels. Good luck with your forging =D
Actually, I dont think you can get more accurate than that. You find inspiration from all sorts of things, you just have to know how to look. If you have problems with that, I would suggest not being an archetect.