Tinytimi, I think the real answer lies in a combination of what's been written before. In my experience, the best way to fill your throne roon is to play AS THOUGH you were going for a really high score. But I don't think it's the score itself that fires off the throne room improvements.
So here's how I would do it (roughly in order)...
* Use a custom world with large map, large land mass and continents but otherwise random.
* Go for world domination. If that means you have to switch on the "Bloodlust" option, so be it (though I personally think that reduces the challenge).
* When you have NEARLY taken over the whole world with the government of your choice (me, I like Communism for doing that) STOP! Make sure there's only one other civ left apart from you, and make sure they have just one city.
* Switch to Democracy.
* Make sure all your cities have aquaducts, sewage systems, supermarkets, doubly irrigated food squares, and railroads on every land square.
* Change the terrain if necessary to maximise food production.
* Set most of your cities to producing Capitalization (to pay for all your maintenance).
* Set the luxury to 100% to get "we love the president days". Most of your cities will grow one point a turn. Many of these turns will give you throne room improvements.
* If things are marginal, change all your engineers into new cities and build them up too.
* At this point, if you've got a LOT of patience, you can set about that really high score too.
HTH
