Ideas for counter-strike: source map

Hello I have made a few small maps already and I am still learning.
I want to start with a little bigger project for now and I am asking for some ideas for a Bomb defuse map. I dont want to make a minigame map or surf map or something because I am not ready for that yet.
Bomb defuse looks good for me to start with as a project, but I dont know how I should make the enviroment. Should I make it urban, woods, snow, grass, building, other ideas?
And what about the weather? Snow, rain, night, dawn, sunny,....

Just place some very good ideas for what kind of map you would like to see.
No impossible things please I am far from pro at Source SDK hammer editor.

Thanks