Making a miter cut requires good measurements and then a little bit of patience when making the cut. Always double-check your measurements before your cut, because the best miter cut is not worth much, if the measurements are off. Miter cuts are usually made in a miter box, which is nothing more than an old- fashioned backsaw mounted on a swivel joint, so that the saw can be adjusted to almost any angle. Today many woodworkers use power miter boxes, which are similar to the old backsaw in many ways. A power miter box has the added advantage of being able to saw off mere slivers of wood, if you first cut is not exact.
Mark the cut on the piece of wood you want to cut.
Adjust the saw (or saw blade) so that it lines up perfectly with the marks on your board. If you are making square boxes or picture frames, you can just set your angle for cutting at precisely 45-degrees.
Begin your cut with a few backstrokes of the saw. If you are using a power tool, all you need to do is gently lower the blade onto the board. Make sure your turn the blade on before it comes in contact with the wood.
Cut the board with vigorous steady strokes. Use as much of the saw as possible when cutting.
Finish the cut with light easy strokes, so as not to tear the wood, when the saw finally passes through the wood.
Lightly sand the cut with medium grade sandpaper.