I also like to form an inner ring of cities at a distance of 5.0 or 5.5 from my capital. This is close enough to the capital to provide good support and small amounts of corruption (early on), but far enough to be able to build a decent number of cities in my innermost ring. Cities outside this innermost ring get a big jump in corruption, so you want a good number of cities on this 1st ring. If you haven't already done so, read the Strategy Article on Ring City Placement (RCP).
Fast growth is essential. Recognize the tiles that are best for population growth and build cities that use them. A capital with bonus food tiles and a granary will allow you to flood the map with Settlers!
There are articles on building Settler Factories around (Bamspeedy has a link in his signature to a very good article)
Forbidden Palaces: I use 3 ways to build it. If militaristic, and/or I'm being aggresive, depend on a Great Leader to build it far away from the capital. Otherwise I can either build it close to my Capital in a high-production city, than do a Palace Jump to shift the capital far away (takes planning; read the Article), or I can build it in a fringe city, 10 spaces away or so, and get WeLoveTheKingDay going to get as much production as I can get, and wait a while.
Lastly, chances are good that you're going to have to take someone else's space away to fully develop your empire. Make plans for this - establish embassies with potential allies, form an army, do a mass-upgrade, declare War, sign Alliances, blitz them. Repeat as needed.