Vertical lines: They help lift the gaze upward and make interiors appear higher than they really are.
Horizontal Line: They help create length and lower the ceiling of a space.
Curved lines: They help soften a room and help to take up space in an interior. Also they give an illusion of depth to a more narrow space.
Diagonal lines: They help lead the eye into the space to the point where the lines converge. They also help bring life to a space, as well as direct the eye upward and downwards.
Forms: Forms help to define objects in space. Forms also help to take up space in either a real or implied way.
Texture: They help to make a space intimate and grounded. Textures also help to add contrast to a space.
Light: Light helps to enhance a room. It also helps to create an illusion of space.
Pattern: They help to make any space feel calm and welcoming. They also help to make the room feel larger.
Scale: Scale helps to define the size of an item in relationship to something else. Scale helps to make a room look proportional.
Proportion: Proportion is a placement of objects within a space. Proportion helps to create balance in a space.
Symmetrical balance: It helps to make a room feel more harmonious and inviting. It helps to make the room feel balanced and whole.
Asymmetrical balance: It helps to create a space look more active. It also helps to create a room look balanced with a sense of the same weight on each side.
Radial balance: Radial balance helps to draw the attention inwards. It also helps to create focus on a central item.
Repetition: Repetition helps to lead our eye throughout the room seamlessly. It also helps to create a sense of rhythm.
Transition: Transition helps to lead our eye throughout a space. Also it can help add light and movement to a space.
Gradation: It helps to create a subtle rhythm throughout a space. It also helps to draw our eye throughout the gradation.
Focal point: It helps to draw attention to a particular object. It helps to anchor the rest of the decor in the room.