Two Story Map. At bottom floor there are two spawn corners. T's Spawn in one corner. Ct's spawn in the diagonal corner. There is no way out of the spawn area except up to the second floo. At second floor you can battle or go back down to the middle of the first floor (not spawn points). Crates are all over the place!! TRY IT OUT!! Feel free to comment
another thing to start trying is atmosphere. besides making a leaky, dirty, falling-apart dry wall ceiling (and maybe even a small puddle with dripping sounds near it) instead of bricks, you can use things that will never be used just to add to a feeling of reality. try putting a door for the "entrance" of the building, that doesn't really do anything but look good. maybe a wooden one with a rounded top. put windows on one side of the building with glass, and outside of there put a flipped copy of the building's side to show that you're in a neighborhood. if you want to get really into it, put a street and sidewalks with a small stairway in front of each door.
maybe you can really expand this map. put an emergency fire exit in a side window that goes into an alley with a dumpster. make six copies of this building (if it's small enough. i'll find out for myself soon.) and put three on each side of the street. put doorbells on them. put a few ct's in one and t's in the other. maybe make a hostage rescue map.
If you need any help with these things feel free to email me.