It isn't always possible to get a group of players together on a regular basis to play a narrative campaign. This means that sometimes you have to find a single opponent and challenge them to a narrative game. With a single regular opponent things become much more simpler if a less impressive. Such games can still be fun though and you don't have to worry about players not meeting up often enough. You and your opponent can take your time and enjoy the details.
The layout below (taken from a rather nice blog entitled Going On Campaign) is a great example of how to play a one on one narrative. The idea is that one player plays the attacking force and the other, obviously, the defender. You play a scout battle and the outcome determines which way the war goes. If the attacker wins then things become a sabotage attempt and so forth. You could just play a game for each one or you could come up with your own scenarios or special rules to match what is written below.
The only problem with this sort of set up is that once you have played the third round, it is obvious which player has won over all. You are simply playing to see whether it is a major or minor victory. This could lead to one player just dropping the whole thing because they can't win. The problem with narrative games in general. You need an opponent who is just as dedicated to the outcome, good or bad, as you are. It is still a good but basic start to narrative play.