For example, I was repairing an Animal Artistry mini resin's legs today (that's the picture of him before the accident). After inserting wire into his leg and sculpting over the repair, I had a tiny glob of apoxie left over. So I smooshed it in place on another piece that is in progress. Of course, the loss of a small amount of apoxie will not bring my productivity to a screeching halt (I have plenty of other distractions for that to happen), but planning ahead so that I always have an in progress piece in need of filler keeps things humming along. By so doing, that little model will be ready for sculptural detailing next time I go at it with apoxie, as the fill work is now done.
Another productivity saver for me is working in batches. I rarely work on one model at a time, especially when it comes to prepping. I usually prep in batches of about a half dozen models. They all get their seams cleaned, then all get a bath in Comet, and so on. Why get the mess out for just one model at a time? This is true when working with pastels, too. Pastels make such a mess of my work table, that I usually try to work in batches of about three models at a time (more than that is more distracting than helpful for me personally). They aren't all the same color (I'm not mixing batches of wet paint that need to be used up), but they all go through the pastel phase together. Then I clean up my work area completely and they all go through the detailing stage together, whether one takes 5 hours or 50 hours to detail. In this case, I am working with wet paint for eyes and hooves and I'm less likely to waste paint on those small areas if I have more models to use it on. And when I'm done, hopefully I have another 3 models already prepped from the last prepping session to start on.
:D