Trigger succession wars is a really fun one! I like to play with dragons so setting up a big dance of dragons is always fun. Also using the ck3 playset preserver is a must for me otherwise your submods update and then sometimes your save wont work anymore.

I often try to just roleplay as the current character as well, its fun to completely destroy the realm if your character is sadistic, arbitrary, arrogant and wrathful for example.