Here's a new one, peace tours. When a war ends part of the peace terms should be allowing diplomats to tour the realms (or key parts of them) and endorse the new peace among the people (by praising the former foe in regions that have deep disdain for them). This gives diplomats more to do and creates new possibilities for intrigue and betrayal.
I like this, a pity it wasn't proposed back when realms had a lot more nobles (and thus courtiers).
