I’m making some boxes and after changing the joint design multiple times, I decided to go with splined miter joints.
This, of course, requires multiple miter cuts and a way to cut the spline slots.
Here is the jig I made to cut the miters.
It can also be turned around to make straight cuts.
I made these supports to fit on my cross cut sled to cut the spline slots.
There is no such thing as scrap, just pieces for future jigs.
-- Learning to retire in Tampa, apparently it's not all that hard.