For some reason, I'm finding it difficult.
I just can't seem to save up for building Lords. I started with two, and I'm still using them, although they're starting to become insufficient.
Nagas keep attacking, and they even manage to take my cities. And I'm constantly short on mana.
I guess I'll have to save up for Lords after all. But I just enjoy building up my castles and making them comfortable.

I took cities quickly: a Fortress and the city closest to the starting city in the first week, a Dungeon in the second, and the northeastern city near the portal in the third. Abyss Demons are strong, but by the time you have three cities, they might not be enough. After that, you can relax and develop your cities. Nagas? Just don't attack them; the portal to their city is near the Orc capital, where Tohunga is located. They'll come after you around the second month of the game. Portals between cities will save you from being captured.