A second light buys you control and costs you the sitting. Every extra stand is another minute the subject spends waiting and another reason for them to stiffen up.
The setup
One window, one bounce card, and the subject turned so the light falls across rather than into the face. If the room has no window, one bare source through a doorway does the same job.
Why it works
Forty-five minutes with one light produces more usable frames than ninety with three. The subject relaxes because nothing is being adjusted around them, and the pictures stop looking like corporate headshots.
What I still carry
A collapsible reflector and a black flag. That is the whole kit — the flag matters more than the fill.