I'm working on a system to maximize country size while providing border cities with close neighbors. I start with one city 4 squares away directly NW, SE, SW, or NE of the capital. That gives it 12 culture spaces. Then I go 3 more in the same direction for the next city. That gives the two secondary cities each 9 squares with 3 up for grabs between them. If possible, I do that again for the fourth city. The 2nd and 4th city then become part of cities ringing the 3rd city (which will eventually get a palace)
X----X---X---X
The ring looks like this (half of it, anyway):
Code:
X
X -|- X
|- | -|
| | |
O----X---O---X
The cities marked with O have the full number of squares to grow into; the X's are used as smaller 'fort' cities. In the early game they are pretty much all evenly sized. All of the X cities have two cities who can reinforce it in one turn, and the main city can reinforce it in two turns.
Build a similar ring in each feasible direction. This design allows me to capture land quickly, and on a large map corruption begins being felt around the area of the 4th city. If I build beyond that point I build 3x3-square cities. The ring design also leaves room for 3x3 cities at the corners, and allows them to be reinforced quickly. This provides a LOT of cultural coverage immediately. It allows me to meet the border of neighboring civs quickly, establishing barracks and a cultural improvement. I can backfill gaps in my coverage later. If I have the chance to expand into the corner between rings, I use 3x3 cities. Of course the placement varies a little with terrain.
My major goal is to have citizens working every single plot of land I own.