Just curious, but what's the common way of tweaking with maps among MODs? I assume the most common tool is good ol' MSP, but I've noticed that some have upped some maps that look "generated" with more advanced software. I'm very fond of maps that are pleasing to the eye and have poked around a bit to find ways to make it easier for both MODs and players alike.
The technique I'd like to recommend is to use multi-layered maps in GIMP. Now, I know this is by no means a revolution - I expect some MODs to have adopted it long ago and use it regularily. Still, since GIMP is free to download, there's no reason to combine the layers to export it when the update is finished. The MOD can simply upload the multi-layered map for the players to download and open. Better still, both methods can be used for quick overview while reading the update and deeper study later on when planning orders.
Allow me to demonstrate with the map below of a setting I was tweaking around with. By simply toggling the view button in the Layers window, you can switch between terrain view and map view, toggle cities, roads and borders, all according to how you prefer to observe the situation. This could easily be expanded to add units, trade routes, notable battles as well as record former borders. The possibilities are nearly endless, and may add to or replace stats and modifiers such as trade centers, alliance overviews, religions etc.
The best part about this is that GIMP is hardly any more advanced than MSP. Sure, it's got heaps of tools, but for NESing, it's like MSP with the option of multiple layers. What do you guys think? I sure hope I'm not the only one cringing when I open a NES thread to find that the map looks beyond hideous.
YOU CAN INSTALL GIMP FOR FREE HERE: http://www.gimp.org/downloads/