Moderator Action: This isn't quite civ-based, so I'm moving it to the Other Games forum. A toss-up between that, and OT, but it's more game-related.
Anyway, on the topic of making strategy games, I think that's kind of broad, and they fall into 2 main categories. (You know, I could write a thesis on this if I wanted... Why aren't there any good game making college courses in Baltimore?

But, I'll try to keep it short.)
RTS - Real Time Strategy (geared more towards MP)
TBS - Turn Based Strategy (geared more towards SP)
Most strategies are war-based strategies. (Civilization, Stratego, War/Starcaft) that usually follow a basic path:
"Collect resources. Build units".
Some games don't collect resources, since you start off with preset units (sort of like Stratego or Chess.). A game like Civ3, or Age of Empires adds a trade and diplomacy element to strategy, which I think works better in a turn-based environment. That is because the time element tends to move too quickly in a RTS game. In a TBS, you are able to plan ahead.
The idea of "design" itself is rather broad, without a well thought out plan of what you want to do. If you want to use the SDLC (Software Development Life Cycle), you can add 3 steps prior, the first being your main idea of the game. (i.e., "I want to create a game that does XYZ). Second is feasibility, which would deal with the time you think it would require to make such a game, and the resources needed. (This is why most companies just don't accept any/all game proposals/solicitations). Making a game costs a lot of money. Then there's "Analysis", what do you want the game to do? (Wants and Musts are the major parts of this. The "Wants" is also known as "The Wishlist"). To use an anology, take Civ3 for example. One feature might been a "Must", like culture. Then, figure out how culture will work before you actually design it. The next step is the design phase, where you start to draw up what the game will look like. I think this is the "prototype" phase, where they don't have the code yet, but its' close. It's putting your priorities together. That is, all of the musts, and a few, some, or all of the "wants". The "wants" are things that might be affected due to time. (any additions might be part of an expansion). Then comes the fun part! Coding, and Testing. Techincally, these are 2 seperate steps, but they go hand in hand. Write the code, then at about 90% through, have testers start to test the code. Then, it's getting it out into the market ("Implementation"), then "Maintenence", which is equal to "patches" in the gaming world.
So, what would be my ideal strategy game, and how would I make it? I don't know -- atleast nothing that I can write in 100% full detail in just 5 minutes. Maybe it's just my Software Analysis professor's voice etched in the back of my head (*shudders* - learned a LOT in that class! and it was intense, and hard, too!), but writing something in 5 minutes just doesn't seem normal... I'll try to come up with something.
