So, let me first say that I've been modding for Oblivion/FO3 since Oblivion came out, so I know what kinds of projects get finished, what don't, and how to pace myself. I've decided that I'd like to make a TC. But before you scoff at it, listen at what I'm asking. The thing about this project, is that it'll be playable once only a fraction of it is complete, because instead of giving myself a giant worldspace to flesh out and hundreds of NPCs to author, I'm going to start extremely small, building the place one small area at a time. First will come the starting area, then the area immediately around it, and from there, well, I won't even plan it out, I'll think about it when I get to it. I'm undertaking this because I feel that in a way the Fallout series has gone as far as it can in time without completely losing its feel of post-apocalypse-ness, and I'd like to make something that'll explore what it'd would've been like to be around when the bombs actually fell.
So what I need are tips on creating a small worldspace. I've tried it before, but I've never really been able to get my heightmaps to work properly, and the worldspace always keeps adding those irremovable boundary cells any time I get to close to the edge of the terrain (grrr). Anyway, a couple of pointers for this would be nice.