Has anyone had success bringing a drying cutting back from the brink?

I started a cutting from a large local tree about a month ago. I think I moved the twig from baggie to Dixie cup a bit early. There were initials, but no roots. The twig developed small leaves about a week after I moved it to a cup. The leaves stopped growing at some point, and now they're bone dry. I can't tell if any roots have developed.

Any tips for salvaging this guy?

That is precisely the point of rooting cuttings in clear containers (cups, or whatever), so that you can assess (see) root development. It is not unusual for a cutting to have leaf growth and then lose it. The leaf growth is supported by the stored energy in the cutting, whether there are roots or not. It is possibole that the cutting is fine, and will devlop roots and sprout new vegetative growth from a lower node in time, but that outcome has a lower percentage probability.