I'm starting to settle into a thought process of the following:
Tradition --> Piety (Cultural)
Tradition --> Patronage (partial) --> Rationalism (Science)
Liberty --> Commerce (Domination, Rex opening)
Honor --> Commerce (Domination, Rush opening)
Edit to add: Granted, it does depend on map/situation, I'm just talking about on average/general approaches. Also, Tradition --> Rationalism straight out if can get to Renaissance in time, but I often find I don't make it in time, but I also play a lot of France.
Another reason why I find that I almost select Tradition by default most of the time is that REXing leads to so many diplo hits that it's impossible to stay peaceful much of the time. "You're building cities too aggressively," "You built in my territory," "Now, as a result, I covet your land," "You broke your promise to not settle by me, since I think that all of the land is mine and you settled another city," "We're at war because I dislike you," "I dislike you because we used to be at war," "My friend denounced you because you settled next to him," etc. etc.