Step 1: For easy crown molding installation, start by finding the spring angle.
Step 2: Calculate the corner angle measurement.
Step 3: Place the molding upside down, flat, on a miter saw table. Set the miter and bevel angles. Overcut molding by 1/4 inch per 10-foot length to allow for spring fitting.
Step 4: Add urethane millwork adhesive to the back and all joints of molding pieces.
Step 5: Spring-fit molding into place as tightly as possible to help make seams disappear.
Step 6: Secure molding in place with either a pneumatic nailer or hammer and nails.
Step 7: Spackle butt joint seams.
Step 8: Caulk ceiling seam to blend molding into ceiling.
Source: Style-Mark, Inc.