In the development of magical practice, there is a next step from striking pacts with supernatural entities capable of imbuing power into mortal users. If this persists within a community long enough, that community will inevitably figure out how to replicate some of those powers as a consequence of their innovation over how to use those powers. The subsequent refinement into a systematized practice is much like how early martial art systems came to be, which is why I refer to these types of magic-users as "crafts". This does not mean that they comprehend what those powers really are, or how they work, so we're not talking about a proper application of science and engineering to the use of magic (yet). We're talking about those who figured out, over time, through a simple process of accidental discovery and later refinement into a systematized practice. In short, this is what I call a "craft".
A craft is a system of magical practice wherein the magic-user learns to harness some combination of discovered knowledge and practical application that produces manifest effects in the physical world. The comparison to martial arts traditions is an apt one, and another apt comparison is to tradesmen of a pre-modern or early-modern sort. In both cases, the knowledge itself is considered valuable due to the power of the effects it produces. Because it is so valuable, access to it must be kept away from the many and restricted to a few who have proven their worth to the keepers of these secrets. What we are talking about here is a mystery cult. These magic-users are the sort who view secrecy and privacy as values greater than any other than survival of those secrets.
The most obvious Occupations in the game that follow this model are the Druid variations from RIFTS: England. (The Millennium Druid is of the Pact sort.) They possess and apply a body of knowledge, maintained through secrecy over long periods of time, that has demonstrable supernatural effects and recruit/train through an initiatory process. They are not dependent upon another entity, in whole or in part, for their power but their comprehension of is lacking; within their base of knowledge what they know makes sense, but errors of judgement and a lack of cultural support for proper inquiry and research (often due to isolation) means that their often trapped in a narrow paradigm with strong boundary conditions that inhibit proper breakthroughs of new discovery. The subculture of a craft emphasizes tradition and conservatism for legacy reasons, reasons that have to do with the craft's origins that have not been properly processed and put into its place, and only sometimes due to those conditions persisting.
The other thing about crafts is that they are, in the long-term, an unstable state. Either they collapse under the weight of their conservatism and secrecy or they complete the transition into a full-fledged discipline akin to that of a real-world scientist or engineer. This is because of how they acquire and maintain the knowledge that permits their powers to exist; accidental discovery is a thing, where someone does something that works but is not expected, and eventually it is both reproduced and transmitted to others. This process inevitably reveals patterns, and those patterns reveal that these powers can be studied, researched, and developed; sub-cultural resistance to such things comes up, and either the progressive elements win and transition to a proper discipline occurs or the conservatives win and the status quo persists- and if this remains long enough then the craft collapses due to being unable to change as their environment changes, destroying them.
Therefore, moreso than most, playing and running a craft-based magic-user means knowing what the current state of that craft's subculture is; your man's experience with this subculture matters greatly towards how he views his magic and how he uses it. Playing a Druid is not playing a Vanguard, and playing one of those 10 years earlier is not default time. Playing the culture game is necessary for these sorts of characters, and in later posts I'll show how this works through examples.