Most of the time when printing a negative for the first time, I can arrive at a print with the refining crop, exposure, dodges, and burns to satisfy me with 4 to 6 sheet of paper. Happily, with the developer, dilution, and amount of old brown that I use, the prints "turn the corner" from clay/green to the pinky-blackish tones that I prefer at about print #3 or 4, and the developer begins to die about print #6 or 7. So as long as I pay attention, I can hit the window and get 3 to 4 finished prints from one negative in a single session.
I feel that I am most productive in printing sessions of around 2 hours, which is about the time it takes me to work up a finished print and get to the tones I like. So I seldom, if ever, replenish or mix up new developer.