We have an "Old Italian" Tuscan theme in our kitchen. Pictures & color are nice, but I wanted to go a few steps further.
Step 1: Build a Frame
Once you measure your entrance way cut out some plywood and screw some 2x4s onto the side. I used a hand saw to cut the 2x4s the same angle as the archway frame because my miter saw wouldn't cut an angle that sharp. You will probably want to use the frame as a stencil for your drywall before you screw the frame into the entrance way.