I had a position as an unpaid assistant instructor of t'ai chi, it was one of my favorite activities ever. Like the kung fu instructor who posted earlier, gave me a chance to discuss all sorts of fascinating aspects. I haven't done this in several years, but I plan to do it again someday, perhaps not until I retire (which I hope will be within several years).
My paid job is as a lawyer. I won't talk about my current position because I don't like it since they changed the job requirements. Previously, here and at a previous employer, I worked on contracts - identifying the contractual needs, writing the documents, negotiating the deals. That was a great practice and I'm trying to get back to that. The aspects that require personal interaction such as client counseling and negotiation took personal development on my part, but that actually benefited me as well as enabled me to do better with the work itself. Frankly I was aided in that by CLE seminars on topics of negotiation in particular ... as well as practice, practice, practice.
My favorite contracting work was in the area of technology agreements, also telecommunications which is a form of technology of course. It isn't surprising that technology and intellectual property interest me as the subject matter for contracts - that's stuff that probably any INTP would eat up. Probably why I consider working on technology contracts to be like brain candy, and will be happy when I can get "back there".
I have a new INTP friend who quite interestingly is a truck driver / instructor. He's been doing truck driving work for 30 years and a number of years ago they added instructional work to his duties. So everywhere he's driving, he has an apprentice or student driver. This allows him to include the theoretical knowledge with just enough personal interaction that's enjoyable and good for him. I also suspect that the hands-on tangible aspects of the work, including attention to safety detail, probably has helped him be a better balanced, scheduled, and structured person, probably to his overall benefit. He does come across to me as well-balanced, which I think is very nice (blush).
Someday I hope to add another position, sailing instructor. I used to help teach sailing, mainly when I was in college and part of the sailing club. I envision that in retirement, I should be able to engage in this, whether paid or unpaid.
When I was in high school, I had a part-time job I loved, working in a music store. Actually it was a chain of music stores, most days I worked back in the inventory area and sometimes I was out on the retail floor helping customers. Since I played the violin and recorder as a youth, this job was great because it "played" (heh) to my musical interests, which I'm guessing is another INTP trait. The interpersonal interaction wasn't too much, and I was happy enough interacting with customers who were also musically inclined because I could respect that interest.
The original question included the component, a job that doesn't require too much training. That music store job I had in high school didn't require any training, at least none that I can recall. Previously I'd worked a minor retail job (part-time holiday help at a major retailer) and I was a musician, so those things helped, but I don't know that they were absolutely necessary.
