How Do You Install Crown Molding?

I am not an expert but I figured it out for myself a few times.  The trick for me was to get it into the miter box the right way.  It will fit real nice into the 90 deg. Angle of a miter box.  Problem is--that won't work.  45's cut that way won't come even close to fitting together!  It has to be cut exactly as it goes up to the ceiling.  The bottom of the molding (the flat spot that goes against the wall) has to go against the "wall" of the miter box at the bottom.  The rest of the molding will be unsupported because you have no ceiling to support it in the box.  It helps to have assistance while it is cut.  These instructions may be obsolete with modern tools but the orientation of the molding in the miter box was my problem.