Call me old-fashioned...
I proof everything. A contact print on grade 2 gives you a ton of information regarding contrast, exposure and possible print manipulations. Being able to look at the proof and come up with a contrast grade that is correct alone saves you lots of paper.
If you already have a smaller print of the one you want to print larger, and have kept good printing records, you have even more information and can use that as a starting point. Experience will tell you what things you usually have to do when going larger: a bit more contrast, printing down or burning down some highlight areas, dodging up a featureless shadow, etc., etc.
I always start with a simple test strip to find my basic exposure (based on the highlights) regardless. If I have a print already, I have a good idea of the contrast I want. If not, I base the starting contrast on the proof I have. If there are areas of obvious dodging/burning, I might make another test strip or two to arrive at a starting point for the dodging/burning. I then just make a print, full size, and spend some time in front of it figuring out my next move(s).
My maxim is, "waste time, not paper." I dry the print down, tack it up on the white board and sit, with paper and pencil in hand sketching out the scheme for the next print. This includes changes in exposure, dodging, burning, etc. If I need to switch contrast grades, however, I'll make a new test strip (or set of strips) and make another full-size print on the right contrast paper/setting and set about deciding what to do next with it. I spend a lot of time doing this. It is surprising how many things occur to me simply by spending 20 minutes or so living with the image.
I then make another full size print which includes all the refinements I have planned. If I'm lucky and my time planning has not been wasted, I have a much better print on the second sheet. The process of looking and planning gets reiterated till I have a print that I think sings. If It won't sing after several tries, or I hit a dead end, I'll move on to another negative, but usually I've selected a negative that has potential from the proofs.
So, in the worst case, I've changed contrast a couple of times, used up a couple of prints to get dodging and burning down and by the time I get to a final print I've used up a few test strips and 4-6 sheets of paper. I then make a run of several prints; three to five depending on the difficulty of making the print. In the end, I have as many or more final exhibition prints as the number of sheets I used refining. That comes out to roughly one finished print for every two sheets of paper. Economical enough for me.
I spend all that money that others spend on enlarging meters and fancy timers on paper. I print with a footswitch and a metronome.