What base script do you usually start with to make these changes? More inland seas would be nice instead of oceans. Is it just a matter of opening the map script and changing numbers around?
90% of the time, I start with the Communitas map script or the PerfectWorld3 map script. I'll open the file in Notepad, and these lines are rather early in the document:
--Percent of land tiles on the map.
mglobal.landPercent = 0.34
I'll then change 34 to something higher. Since I've been going with more civilizations lately, I've been changing 34 to 63. The map is still tightly-packed, but water is much less dominant on the maps.
I'll also tinker with the percentage of the land that's mountain tiles, swamp tiles, desert tiles, etc. In the Communitas map file (found
*here*), those values are under the "Terrain," "Features," and "Rain" headings. The file is really nicely laid-out in that each variable has a descriptor by it so that you know what you're tinkering with. I'd spend a bit of time tinkering with each value and then generating random maps in the WorldBuilder to see if and how each variable changes things.
Finally, I don't get to play many full games of civ.. maybe one or two a month. So, in the interest of guaranteeing that my game doesn't give me a map-related letdown, I have an odd habit: I generate random maps in WorldBuilder well in advance of my next game until I find one that I really, really like. Then, I name it, save it, and don't look at it for a few weeks. By the time Game Day arrives, I've long forgotten what the map looks like, especially with a random starting location.