Acquiring general virtues in play

So, arts and abilities can be raised through experience, stats can be improved through creo rituals, hermetic and supernatural virtues can be gained by initiation into mysteries but is there a canon way to gain an affinity or Good Teacher or Rapid Convalescence? Does anyone have tested houserules for gaining such things, with or without ritual magic? Any suggestions?

General Virtues , that affect you physically or mentally , should be possible through Momentary Creo Rituals.
The usual suggestions would be a Minor Mystery or Minor Breakthrough.
Minor , because you can already increase characteristics.
There are no guidelines for adding Virtues , but would be minimum level 20 for a ritual.

The Fertility Ritual on page 56 in Ancient Magic might be worth a look.
You would have to research a version that worked other than during conception.

No such rules IIRC. Have done it by SG fiat and fluffing it.

For magi, is there any reason that these couldn't be done through mystery initiation? You'd have to find or create a cult with a script for them which may make it nearly impossible but my understanding was that almost all virtues were open for initiation not just supernatural ones.

How many mystery cults are out there and available anyway? What if you want to start your own?

My way would be to pseudo-initiate the virtue, through entirely mundane means.

For example: Initiate Good Teacher, minor virtue known by "Mystagogue". Use "Teaching" as "Lore" and "Communication" as "Presence"

Script bonus: + 9, target +15; The character must have at least Teaching 3 and Scribe 2 to initiate this virtue.

The character travels to a Great University of Mythic Europe, before the begining of the Michealmas term (+1) The character must find an instructor who will help develop his teaching skills, and pay a substantial amount for the instruction time (+1). The Mystagogue must spend at least one season teaching the art of instruction (+3), after which the initiate must spend a season practicing by tutoring students (+1). In the process, the initiate becomes taken with his own prowess as an instructor and the resepect his students pay him, on the basis of his teaching, rather than what he knows, gaining the minor flaw Overconfident (+3)

The SG and the player agree on a reasonable degree of "initiation" to gain a virtue.

A character might likewise "initiate" "Improved Characteristics" with a new ordeal "annual comitment", representing a commitment in time every year to keep up the virtue (+3-+6 dependin on commitment in time for exercise, for example, to keep up points in strength and stamina.)

Nice.

The Forest (from Guardians of the Forest) is also another possibility to learn pretty much any general (or supernatural/magic, or hermetic) virtue in play. If you don't have the book, it works basically like this. First, you need to earn a few xps in "Forest Lore", by studying the great Hercynian Forest itself. Once you gain a mystical understanding of the Forest (which has its own perks) you'll be able to embark on a path of enlightenment -- first acquiring a minor virtue in exchange for a minor flaw and a quest, and then acquiring a major virtue in exchange for a major flaw and a major quest. Pretty much anything is up for grabs as long as the path "makes sense".

Visiting the Magic Realm is another such possibility (see RoP:M).

Yeah that looks like ok ways to run it.

Although in-character, you can only make the sacrifices and get the fruits that the Forest is offering. So, in-character you cannot get an arbitrary Virtue in this way.