Create a Sense of Mystery. One of the time-tested ways to create an aura is for the insiders to use terms that are not grasped by the majority of the customers. Latin is already taken but that's no problem. We can make up our own terms and phrases. One key point: we must train insiders to mutter this arcane lingo in an off-hand manner so customers will be both confused and awed. The more jargon, the better, especially if it is combined with jokes.
Limit Membership. There won't be much mystery if anyone can join our club and so we must have barriers. In an ideal arrangement, we'll want complete control of all screening so we can restrict competition. We'll do all of this in the name of quality. If formal control is not possible, the intricate nature of our workings should fend off amateurs.
Complicate Matters. All our endeavors must show a bias for complexity and a shunning of simplicity. Complexity favors the interpreters and guess who they are?
Introduce Obsolesence. The machinery and the rules must frequently change lest our customers get too confident and assume they can do without us. We must always charge for resolving the problems created by the changes we have engineered.
Punish Renegades. Occasionally, a member might decide to abandon our accepted practices. This deviation must always be punished. It is important that frustrated customers quickly realize that any problem encountered with one of our members will only be duplicated should they visit another.
Discourage Questioning. Free questions are only permitted if the answers are so convoluted that the person who had the temerity to ask will be discouraged to do so ever again. Requiring payment for the lengthy and inconvenient answering of questions, however, is desirable.
Create Specialties. Once the profession is established, specialties must be developed. If a member wishes to continue in general practice, then that too will be a specialty. See the above comments regarding mystery and jargon. Multiply their effects.