There are some new tools made especially for installing crown molding. Here's a website, www.crownmoldingconcepts.com , that has a 2 min video that shows an easy, accurate way to measure and cut crown molding. It uses some new tools made especially to measure and then easily cut crown molding on your miter saw. You cut angles but you use dimensions instead of degrees. Check it out.
The video at www.crownmoldingconcepts.com shows how to use new tools for measuring and cutting crown molding.