I couldn't find any tips on how to improve the Piety value of your Generals and Governors apart from the obvious one: Lead a Crusade.
As Crusades don't happen too often, there's to be another way.
Has anyone noticed any value increase when:
- you build a structure from the church line of buildings
- you let a priest/ cardinal join your army
- you did something else

Any tips are appreciated.

R'as