Drill four clearance holes all the way through the filler piece. Apply wood glue to the door, align the filler and clamp it in place. Then drill pilot holes in the door through the clearance holes.

Trimming a wood door with a circular saw without splintering ... deep with a utility knife. We like to clamp a metal straightedge to the door on top of the masking tape along the cutting line.

Rails and stiles are the horizontal and vertical parts that brace and stabilize a door (typically wood). Solid wood rails and stiles can sometimes warp or bow in humid conditions, so if durability ...