Firstly I'm going to preface this by saying I'm very new to the game and probably have no idea what I'm taking about.
In the (admittedly very few) games I have played, my thought process when playing my cards has gone like this:
The sixth card is the most important as there is no way to move the marker after this card so I should save the highest card I will play for last.
The fifth round is the next most important, going down to the first round (as the number of remaining chances for my opponent to interfere with the marker if I have won the round before goes down each round), so I should play my cards in order from lowest to highest.
Is there a strategy for playing your cards that works better than this? I have noticed my opponents have tended to do the same. Is there a better strategy that I'm missing here?
There are a few other considerations:
1. If you have more than six cards, do you want to keep good cards back for scouting?
2. Do you care what the terrain is anyway, or what terrain your opponent might want?
But generally I think your strategy is the one most commonly adopted.
Richard