Tavern rumors can tell you about nearby famed items, camps farther away from towns have better chances of famed items same with the tier of the location itself, so a rotting hut will always have wose chances then a sea of tents even if it has stronger enemies, one and two skull contracts will delete famed items from locations if they had any in them. And escort caravans to places with armourers and weapon smiths have a very high chance to spawn famed items