Place one 1/4-by-3-by-12-inch board on a work surface, with one 3-by-12-inch side resting flat. Mark one 3-inch end of the board with the word “end.” This will allow you to know which end to place on the end of the door.
Position a hinge flat on the board so that the outside edge of the hinge is in 3 inches from the end marked “end,” using a tape measure. Mark the mounting holes on the board with a pencil. This is the door jig. Mark this with the words “door jig.”
Repeat Steps 1 and 2 to mark the door frame jig. Use only the opposite half of the hinge to mark the mounting holes. Mark this jig with the words “door frame jig.”
Place each jig board flat on the table of a drill press. Drill a 1/4-inch hole through the boards at each pencil marking, using the drill press equipped with a 1/4-inch drill bit.