I prefer maps that have more land barriers than most of the existing ones do. The stratigic importance of provinces isn't really there a lot of the time. The economic importance dominates.
Things like bigger impassable mountain ranges (through several provinces) impassable forests, huge wastes... you can do it for any terrain type other than plains or farm land I suppose. Just some map (size doesn't matter [snigger]
) where the land terrain is broken up a bit would be interesting.