Game desing and documentation

I want to ask how are the modeling process of a game(a Torque game). I'm planing to develop a strategy game, and I don't know the documentation process.

I try to use tools like data flow diagram, ER diagram, but that not work very well, I think to the reason is to that is a structured tools.

I want to use UML to modeling the game, but, I don't know if exist a method for modeling real time strategy games.

I try to use class diagram, use-case diagram, sequence diagram, collaboration diagram and state diagram too, but is hard to do this way. I think to exist a game-modeling method, more natural to model games.


Thanks.