Rise of the Dragon
The use of honourifics in Rokugan is complicated. Part of the complication lies in the fact that the formal/informal axis and the respectful/disrespectful axis are the same. That is referring to someone disrespectfully and referring to someone informally use exactly the same language. You need to decide which based on context.
So for example when Ikoma Sozen referred to Akono Mitsuro without any honourific, both Kazuya and Heisuke took that to mean that they must have a very close relationship to be that informal (hence the assumption that they were lovers). Another explanation would be that he was referring to someone so far beneath him that he had to need to treat her with any respect but that interpretation made no sense in the context he was using her name.
Also being too respectful/formal can also be seen as insulting. Essentially one would be seen as being sarcastic (like responding to a request from a friend with “Of course I’d be happy to help, Your Highness.”).
When addressing strangers generally only sama, or san should be used (assuming you wish to be polite). And one should use as specific a name as is available. So if you know a stranger’s name, you should use that, otherwise a family name if they display an appropriate mon, by clan if wearing identifying colours or mon, or just samurai otherwise.
So here is a list of honourifics from most respectful to least.
Used to refer to ones teacher. In that context it is generally the most respectful honourific. It can also be used to refer to any teacher, or learned individual (like say a Doctor or Lawyer).
Used to refer to one’s Lord. This is generally the most respectful general purpose honourific. It can be used with anyone above you in the Celestial Order.
I’m not sure the exact difference between Dono and Sama, just the relative rank (James who’s seen more Anime could probably give an idea of the difference).
Only used between students (in modernish times it’s really only used in the context of martial arts dojos) to refer to a senior student.
The general honourific for someone of a similar rank. Can be used for those beneath you as long as they aren’t too far beneath you in the Celestial Order.
Used with children, or lovers.
Using no honourific with someone’s name indicates that you are so far above them that you have no need to use even basic courtesy.