Guess I fit into the "best to have a plan" approach if the final prints are 16x20 or larger. After picking the "potentials" off the contact sheet, I make 8x10 work prints on RC paper (RC speeds everything up, after all these are work prints). Normally I "gang print" the work prints (I standardize the exposure for all that look similar on the contact sheet), expose 3 or 4, and then shuffle them through the chemicals, pretty much the same as I would tray develop film. So these are "straight" (no manipulation) prints. I select from those the ones interesting enough for "real" larger fiber-base prints. If I'm going 11x14, I figure out the manipulations directly on the FB paper, since I usually get where I want to be in about 4 iterations (plus one more for dry-down). But if I'm going to print larger (expense goes up with size, as you're well aware) I will work out the dodging/burning at the 8x10 RC level, so that when I get to the big print, I have my workplan ready. Not to say that I may not still iterate a little, but much less than hitting the 16x20 "cold" (never tried 20x24). I scale my dodging/burning to keep the same "percentages" on the big print as on the small, since of course the base exposures are different.