First decide the different functions the space will serve. For example, if you have a large space that needs to be living, dining and kitchen use area rugs to define the living and dining spaces and cabinets to define the kitchen. Use pendants, chandeliers, and beams to bring the ceiling to a human scale.
The quote “less is more” can definitely be applied to accessories; too many can create clutter and confusion. Your eye stops on every object so clutter will not allow a smooth visual flow around the room, therefore, creating visual and psychological unrest. Use fewer pieces to give each an importance and select your items based