1.) Add crown molding or picture rail to make the ceiling height seem lower.
2.) Wallpaper is a great way to trick the eye of a lower ceiling and adds a designer look to your space.
3.) Adding decorative elements to the room, for example use beams to create visual interest or add shiplap or wood panel for a little texture.
4.) Less expensive trick is to add task light throughout the space. (table lamps, floor lamps, track lighting) lighting will lead the eyes ways from those super high ceilings.
5.) Designers use this trick all the time. paint a darker color on the ceiling. Painting is a simple diy project that most people can do on themselves.