A few medallions added to a flat ceiling can create interest in a very subtle way! One of the artists I work with cut this stencil for our home from a wallpaper pattern that was similar but smaller. We added it to the ceiling for interest.
There are also replications of the historic ceilings that can be effective on higher ceiling for detailing. For an historic and interesting application check out the Cathedral of the Immaculate Conception recreating the look of the Basilica di Santa Maria Maggiore in Rome. Begin with a base coat of Sherwin Williams Duration Home in matte finish, stencil on sizing and proceed with metallic leaf, aluminum leaf and additional varnishes and stencils.
Here is a creative use of stenciling! It is combined with hand painted tiles for hood detailing is this luxury kitchen.