"System" is a very good word, Andrey. From the point of view of portraiture, the people of the world fall into 2 distinct groups, namely the 5% or so who like the way they look and the 95% who don't (notwithstanding that among the 95% there may be many whom you or I might consider attractive, or even to be flawless beauties - they don't like themselves!). I therefore believe that successful commercial portraiture is a question of applying a flattering formula with minor variations (and of course developing an appropriate professional manner, radiating confidence and enthusiasm, always concentrating fully on the sitter, never fiddling with lighting or other equipment in the presence of the sitter but engaging them in conversation to put them at their ease, etc.).
Originally Posted by Andrey
This, quite frankly, is why, despite the fact that I am a trained professional and quite happily do live demonstrations of portraiture from time to time at camera clubs, etc. shooting either Polaroids which are passed round the audience or digital pics which are projected on a screen, I don't do commercial portraiture, because I find it tedious to constantly re-vamp the same formula in the way which seems essential for commercial success.
I believe you can develop a system only through practice - if you can find subjects which you can try shooting in five or six different ways (and who don't get bored while you shift the lights and camera about, which as I said I would avoid doing with real clients), I feel you would be well on the way to developing the eye which would enable you to decide instantly what set-up to use for a given sitter.