For a long time, part of my main gig was to shoot events, like festivals etc. for a magazine. While most of this was not "portraiture" in the traditional sense, it always involved working with human subjects. Naturally rather shy when I started doing this, I got over that pretty quickly. I had to. It became immediately obvious that the essence of the job was to engage, even to entertain the subjects. The more entertaining I could be, the easier it was, and eventually, I got so good at it that I could often shoot in close quarters for half a day or so before anyone thought to ask me why I was there. I could even direct people, and they'd do what I asked without question. I think I only had maybe three or four uncomfortable episodes in about twelve years.
I had one job for another client which was to shoot portraits of forty or so individual attorneys in their offices for a brochure I like the kind of light you get using a bare tube flash in small white rooms. It gives a direct light component with a nice diffused ambiance, if the balance is just right. With the particular setup I decided to use, I could use either f/5.6 at 8 feet, or f/8 at 5.6 feet. This took care of the technical stuff so I could work fast without having to worry about it. The approach I took was to fasten a flash-head to my head, bolted onto a hard hat. The result was amazing. Some of those guys were really hard, but you'd never know it through the pix. It was sometimes a challenge to subdue the mirth.
This was quite a while ago, and not all my files are in one place. If I can find the job, I'll try to reply to myself with an image or two.