I actually picked this up from Paul Sellers, though not something he specifically discussed. The tip came from a picture in his book; when I saw it I thought “why didn’t I think of that”.
Here is my version of the picture.
When the joint is assembled the marks are permanently hidden by the joint…you don’t have to figure out how to erase them later. A nice way to keep things straight, huh?
-- Make furniture that lasts as long as the tree - Ryan