Fabricate the Frame
Rip the Frame Width: Based on the intended use of the frame and its dimensions, set the table saw to the desired frame width. Depending on the overall size of the frame, rip enough lumber to accommodate all four sides, with plenty of wood to spare.
Miter Cut the Corners: The frame will consist of four sides connected to make 90-degree corners. Each side of the frame will have the ends miter cut at 45 degrees to make the corners square. Place a framing square or speed square on the corner to confirm 90 degrees.
Making the Frame: Pre-drill the frame corner pieces using a pocket hole jig. Apply heavy-duty construction adhesive to the contact edges. Secure the corners by screwing them together.