Measure the wall where you will locate the last piece of molding. For a seamless look, you want the crown molding to stop right at the tile. Transfer the measurements to the back side of the crown molding with a pencil.
Cut an outside miter cut on the end of the crown molding. Set the miter saw at a 45-degree angle. Set the crown molding in place upside down in the miter saw. For a proper cut, rest the bottom edge of the molding on the fence of the miter saw, and rest the other edge on the table.
Use a pneumatic nail gun to nail the last piece of crown molding into place. Butt the crown molding up next to the tile.
Finish off the crown molding by capping the end. Cut another outside miter at a 45-degree angle on a scrap piece of crown molding. Once you have cut the outside miter, reset the miter saw to 90 degrees. Place the scrap piece of crown molding flat on the table of the saw. Use the miter saw to cut the piece of molding. It should come to a point at the bottom edge of the molding.
Glue the cap molding into place on the end of the crown molding with wood glue.