Crown molding can be intimidating, because walls often aren't flat and nailing is difficult. Don't worry. This three-piece system solves those problems. Here we'll show you how to install trim on the walls and ceiling first, then add the crown. The three combined look elegant and go up more easily than a single large piece. We'll also walk you through the tricky cuts at corners.
The secret for a glove-tight fit for trim corners is a coped joint. With this technique you can even make complex crown moldings fit without leaving gaps. http://www.familyhandyman.com/carpentry/trim-carpentry/how-to-cope-joints/view-all