It depends, If I play ortodox inland country, I first put max city tax, max church tax. I migth low max levy from cities/churches so I have better relation.
Then for a long time I change nothing, in mean time I concentrate on raising crown autority and expandingand changing succession law. At that time I do not want to low relationship with feodal vassals. Chabge of succession law demand that all vassals have + to you.
When I finally form empire and establish crown autoryty and succession law I want, I do not need to warry about everyone happiness any more. So, I put Max feodal tax, and continue with expancing with combination with buiding spree.
That work for same time, but eventially you become so incredibly big, you need to have kings vassals and keep them happy and keepping empire happy become a problem.
At that time I drop feodal tax. At that point you useally CAN NOT change laws any one, exept getting them to default. You never get enogth voites, abd they tend to voit for no feodal tax by default.
If I play catolic, it depence. if for example, some place near sea. I tend to go to max city taxes/ min max church levy. I migth even consider to drop church tax to 0, because most bishops pay taxes to Rome anyway,
Then after I expand to my county limit I tend to give new counting to majors ( if place same culture).
So, my income base is taxes from cities and grandcities and republics. Bishops insted provide levies. after that I tend not to change thinks.