I'm beginning work designing the a world for use with a 4E gaming group. The big thing I wanted to get out of the mapping strategy is starting with a small local map. The key is I'd like to be able to grow the map as they explore, gain new pieces of information, etc. I didn't want to necessarily map the entire thing out right out and then just remove the fog, but have the flexibility to design on the fly as I need.

Any suggestions of map styles that are easier/more difficult to do with this goal in mind? Has anybody done this and run into any sorts of problems or difficulties?

Thanks in advance... this is my first thread here and I'm fairly new to mapping.