I've gotten into the habit of putting a "protection" coat of poly on
pieces before gluing them together (er, mill wood, poly, then cut
mortises and tenons) so that I don't have to worry about glue ruining
the finish later. However, I only do one or two thinned coats, and
re-sand and re-finish after gluing.

I've also been finishing drawer bottoms and door panels before
installing them, so I don't get unfinished lines around the edges when
the panels shrink later.