I – I play only as an Orthodox rulers. Or I start as Catholic one but my first “target” is to convert my ruler to orthodoxy. (I guess that’s a zealous part of me). However not by moding, but true breeding and event forcing. I have weird results like huge dynasties of Norman orthodox leaders.
lol, I usually do the opposite! I always start as Catholic or if I start as Orthodox I always try to convert to Catholicism by joining western Kingdoms.
Anyway my house rules are:
1)Always start as a Count. If no pre-existent county inspires me I can create ex-novo a county by starting as a King, creating it, saving and loading and choosing new count dinasty.
2)Not to many King titles, 4 or 5 are enough ("stolen" arab titles such as King of Fatimids or Knightly Orders titles like Teutonic Order doesn't count if well roleplayed)
3)If I inherit big titles (such as King of Germany) or far titles (e.g. King of Portugal while I'm in Finland I will give away that title.
4)Marriages with other cultures are accepted, indeed encouraged. Particularly with other Kings or powerful Dukes' daughters.
5)I'm allowed to modify save file to change the name and the culture of my heirs if they were born with diffent and far cultures (e.g. my heir is named Jose and has Portoguese culture while I'm King of Finland just because his mother is portoguese)
6)Always give titles to other families preferably of the same culture of the King. I do this because IA vassals tend to marry people of the same culture, generating inbreed children. Creating various dinasties can extend the genetic pool and avoids inbreed vassals. My style: 95% Other families dukedoms and Archbishops, 5% my first-born dukedom.
7)Sending the first-born heir (and sometimes also his brothers) as fosterling is always a good thing to do. It's plausible to send him to other kingdoms such as England, France, Germany, Byzantium, Gerusalem, Scotland or even Venice.
8)Generally my games should have a sort of historical and geographical coherence, but sometimes I enjoy playing odd situations like the creation of a gigantic welsh kingdom in Africa. In these cases one primary target is to spread my King culture and religion, using as far as possible other families from my homeland (e.g. Cynfyn family as dukes of Marrakesh, Clydog family as dukes of Fez and so on...)
9)Cheats must be avoided or used only to stop paradoxal situations.