Measure and mark the apex of your cut with a ruler and a pencil. For example, if you are cutting molding for a frame that has outside dimensions of 10 inches by 10 inches, make a pencil mark 10 inches from the end of the molding.
Lay a scrap piece of 2x4 or similar scrap of lumber in the bottom of the miter box. The scrap wood will allow you to cut completely through your molding or other piece without scarring the bottom of the box.
Set the miter box on a flat surface. Arrange the molding in the miter box so that the pencil mark you made on the molding aligns with the apex of the 45 degree slot in the miter box
Hold the molding against the back of the miter box with one hand. Insert the miter saw into the 45 degree slot in the miter box with your other hand. Saw through the molding.
Things You Will Need
- Small wood scrap
- Miter box
- Back saw
- Cut the miter first, then cut the piece of wood to the length required. This way if you make an error or damage the miter end, you can just cut another miter.