My strategy when playing Princes of Florence is rather one-dimensional. I just try to make as many works as possible. Usually I try to complete 6 works. I have done 7 works just once I think. So, this is very much a quantity over quality strategy. So I like the jesters, which improve all my works. I rarely buy bonus cards because I need to save my actions for completing works and buying profession cards. Anyway my focus is on quantity and not on boosting the quality of a single work. I usually don't bid for prestige cards, unless there is nothing else I need.
I think my strategy is pretty narrow because I usually play the 2-player variant. Princes of Florence is a game best played with 5 players. So having only Michelle as my opponent probably distorted my game play. I am quite sure there are other strategies to explore. Also with more players there will be much more competition, and your plans can easily be foiled by others. So with more players the planning will be much more trickier, and you'll have to adjust your plans on the fly if things don't go the way you hope. There may be much more of a survival feel.