As I recall, (and it’s been AWHILE since I last played) I would build fortifications on turn 1, definitely. (Probably even on turn 2) The location would of course be where my forces had their natural stronghold.
As far as units, I would always make it a point to max out my imperial armies (the ones with the little ensign guy holding a flag) with bowmen. Then, they would be prime for kicking a$$ with the whole first-strike ability. Gunners are key too, for the same reason.
And Ronin are also useful, because as I recall, you would purchase X amount, place them on one of your face-down territory cards, and reveal them when that territory is attacked. X surprise swordsmen popping outta nowhere to slice n’ dice your enemies is nothing less than awesome. (especially when you see the look on their face when you announce the Ronin coming out of hiding) :wink: