Clamp the end of the moulding in the vice with the textured side facing you and about 4 inches from the end sticking out on the side of your dominate hand.
Mark a 45-degree angle from the back end of the moulding to the front side using the pencil.
Place the coping saw along the top of the line and make a cut along the line.
Continue cutting through the moulding along the line and using long, continous motions.
Tilt the saw downward on the front as you saw when you get halfway through the moulding. This will cut through the front edge before the back side, preventing splintering on the front.
Cut the rest of the moulding, ending in the back, bottom corner.