I find that the hardest bit about any project is the first steps. Mainly because most of my projects involve a sizable portion of 'winging it'. Also its very hard to continue on a project when its not playing out how you envisaged it. Fortunately at the moment I'm liking what I see.
I've done a small amount of preliminary planning for each of the terran squares (while waiting for instrument results. Real life is not like CSI at all), but I tend to go with what I feel would be interesting terrain to fight over. One thing with my system that I feel is a plus is that it gives long ridge lines, which I have not seen before in Spearhead battles.