An excerpt from Joshua Klein’s forthcoming book, Joined: A Bench Guide to Furniture Joinery:
“When you’re confident everything is perfectly lined up, scribe the angles with your knife. Several gentle and progressively deeper lines are better than one deep line. Do all the right sides first, then come back for the left sides, as you did with the sawing of the tails.
Now you can see why the angles of the dovetails do not need to match each other: the pins are perfectly scribed to their respective tails. This board is not interchangeable with any other board in the world now. Label your joint on the edges of both boards before separating them.
If you are having a hard time seeing the scribed lines on the end grain, you can use a wide chisel to deepen the line a touch. Some folks like to run a pencil inside the knife line. Do whatever you need to do to see those lines clearly. Making the first half of this joint has been relatively low key, but once your tails are scribed it’s time to get persnickety.
With a small square, carry the scribed lines down the show face of the board.
Mark your waste.”