Art of the Portrait

With Deanne's suggestion I have begun a new portrait project. It is still too early to reveal the subject matter, but I will share thoughts on my approach. I would like to to add another gear to my portrait process, but I do not want to over complicate the process and loose my connection and spontaneity with my subject. To take a good portrait, past experience has taught me to minimize the variables. I would love to shoot these portraits with a view camera, but if I do I will stick with available light. Variables are the subject, the location, camera, and light. Each extra subject is an 1/2 a variable, while each light source is a variable. A 35 mm camera is 1/2 variable, a medium format camera 1 variable, and a 4x5 camera 2 variables. For example, if it's just the subject, the sun, and my Hasselblad, that's only 3 variables. Easily I can handle 3 variables (see portrait of Alex). 4 can be a challenge, but I can comfortably handle it. More than 4 variables, and it's just me without an assistant (a good assistant absorbs 2 variables, a great one 3), my efforts will not result in a good photograph. So, my challenge is to add another gear to my work, without over complicating the process and loosing my subject.