Minor Reprimand
This is little more than formally stating that what the mage did was wrong. This formally expresses to other mages in the city that the Consilium considers the act a transgression. (Refer back to the Precept of Recognition for further details.)
Nothing to add here - this can be applied as written.
Major Reprimand
The Consilium instructs other masters to limit their assistance to the mage. In some cases, the Councilors may even warn other cabals or mages against helping the criminal.
This is a good point to talk about what 'assistance' means. I think 'to assist' should describe sharing resources (Mana, Hallows, items), services (mentoring for learning higher non-ruling Arcana, casting spells for each other, helping in personal matters), and knowledge (teaching Rotes, giving advice). Hence, any character who is currently a Master in an Arcanum should refrain from assisting the punished character.
Payment of Debt
The mage must pay a debt, usually in the form of a favor, act or deed. Cabals and orders trade favors, as do masters. If the mage belongs to a society — such as a cabal or order — she must pay on a debt that her society owes another.
The debt is decided by the offended party and should be role-played. This seems open ended and most likely an opportunity to act as a hook.
Minor Penance
The mage must atone for her act by performing a service for the city’s mages. This may be something as simple as re-organizing the contents of a library, standing guard with agents of the Adamantine Arrow or serving as a lone watchman for a few nights.
See, in my magical dream-world I'd suggest the punished player has to write a glimpse describing the service done to the city's mages: it would reflect the degree of punishment, take some work and give players a canvas to roleplay about their crimes or the punishment. However I realize that forcing players to write a glimpse can suck the fun out of it straight away. I'm leaving the suggestion here either way, otherwise I think that going forward maybe flipping the precedent could be a good compromise: the player has -1 scene for the time, since the character is busy doing a service as punishment.
Major Penance
The mage must perform a risky or dangerous act for the benefit of the city’s mages. This could involve scouting an area known for supernatural activity, undertaking a spiritual journey or retrieving a powerful artifact. Note that this punishment actually hints that the mage has potential, since a fool would not be trusted with such an important mission.
Adding to the above point: if the undertaking is more dangerous it's not unreasonable to think that this would dent the character's Mana-pool: in addition to the scene cap, the character loses points of Mana in excess to their Wisdom (or to make it sting more: a flat amount).
Severe Reprimand
The Consilium states bluntly that no one (not even initiates) may aid or assist the offending mage, clarifying the duration of the reprimand. Offering assistance merits the same punishment, “tarring” the collaborator “with the same brush.” The mage is then either instructed to meditate in seclusion or abstain from practicing magic. Failure to comply leads to incarceration.
See the definition of 'assisting' above. It could be argued that characters are expected not to publicly interact with the punished character - private scenes (while frowned upon and bringing their own host of possible consequences) are not forbidden by OOC rules.
Incarceration
The mage is magically confined, surrounded by powerful wards that cripple his magical power. He must meditate on his actions. In many cases, this is done because the mage is dangerous enough that he has risked exposing or seriously weakening the city’s mages, and the Consilium needs time to recover while repairing the damage that’s been done.
The character is not allowed to participate in open or private scenes for the duration of the punishment. 'Visits' (i.e. small, private scenes) and glimpses are okay but the former should be justified in some way (the jailor and the jailed, a Cabal mate visiting, a Guardian interrogating).
Banishment
This is rarely effective, but sometimes used as an alternative to incarceration. The mage is given orders to leave the city, sometimes for a specific period of time. If she returns during that time, she faces incarceration or worse. The stigma can include further details of where the mage must go or what she must do before she returns.
The character is asked to leave the venue, with the possibility of maybe returning at some point in the future.