There are only six parts to the entire cabinet I’m building as an upcoming project for 360 Woodworking. (There are a lot of drawers, though.) As is the case most of the time, milling comes first. This is a small project, so milling work is quick.
Because I’m using narrow stock there are 10 pieces of rough lumber that I need to keep straight. Those 10 pieces become the case sides, top and two dividers. All the piece came from three boards and are about the same lengths and mill to the same thickness. Plus, I’m milling it all at once. To make sure that I don’t grab the wrong piece as I go to glue-up my panels, I mark the ends with different symbols.
As you can see in the above photo, the stock that becomes the sides has a single line from face to face. The three pieces that become the two dividers have a double line from face to face, and the top and bottom of the case have a line parallel with the faces.
It’s not higher math. It’s in no way scientific. It just works for me. KISS.