I just got back from my week of teaching at the Port Townsend School of Woodworking. The class was on building a frame and panel nightstand (or side table), with haunched mortise and tenon joinery (and half-blind dovetails for the upper stretchers), all of which was cut by hand. In other words, this was a seriously ambitious project for a 5-day class. But also a project that really put into practice the fundamentals of solid wood case construction.
The killer day was Wednesday, which was when we cut and fit all of the tenons to the mortises. It was a long, hard day, but that really put us on the path to completion on Friday. One of the things that helped get everyone through the process was a dead-simple jig.
The “jig of the week” was a simple 3/8” by 1 ¼” by 3” block that fit into the grooves for the panel in the legs, the rails, and for the case bottom. This helped with mortise layout and was invaluable in fitting the tenons to the mortises (you could easily tell where to remove wood from the tenon to keep the grooves aligned by sliding this stick out along the tenon while still in the groove in the rail).
I’m not sure that this is something that would be as helpful in different situations, but here, where the legs and rails were not aligned flush but the grooves needed to be, it was something everyone used over and over. And everyone’s grooves lined up perfectly.