Measure and cut the piece of molding that will have the dead end. Cut the end of the molding with the dead end at a 45-degree angle outside cut. Place the molding on the table saw with the bottom of the molding facing up and the back resting against the back of the saw. Set the saw at a 45-degree angle, and make the cut at the desired length.
Cut a second piece of molding with an inside cut. Place the molding on the saw with the bottom facing down and the back up against the back of the saw. Cut the molding at a 45-degree angle.
Move the saw blade to a 90-degree angle, or to the zero mark on the table. Turn the second piece of molding over. The back side of the molding should be facing up.
Align the saw blade to the cut line on the back of the second piece of molding. Cut the molding on this line. This will create a 90-degree cut. You should be left with a small piece and a big piece. The small piece should have a 90-degree angle and a 45-degree inside angle.
Match the 45-degree inside angle of the small piece you just cut to the outside angle of the piece that was cut in step one. Apply a thin line of painter's caulk to the seams of the molding. Press against the wall, and hold for a few seconds. Nail the two moldings to the wall.