You have to know the rule well in order to break it or stick with it when the visual need
so any design must have this four elements : Contrast, Repettion, Alignment, Proximity
Contrast: You want to avoid elements on the page that are similar. If you choose to make things like type, color, size, line thickness, shapes, space, etc. not the same, you should make them very different.
Contrast is often the most important aspect of design since it is what makes a reader look at the page in the first place. The basic purpose of contrast is to create an interest on the page and to help organize the information. You can get contrast through your typeface choices, line thicknesses, colors, shapes, sizes, space, etc. When using contrast do it with strength. Avoid contrasting a sort of heavy line with a sort of heavier line or contrasting brown text with black headlines. If the items are not exactly the same, make them very different.
Repetition: Repeat visual elements (colors, shapes, textures, spatial relationships, line thicknesses, fonts, sizes, graphic concepts, etc.) of the design throughout the piece. This develops organization and strengthens the unity. You can also think of repetition as consistency. The basic purpose of repetition is to unify and to add visual interest. You can get repetition by pushing existing consistencies a little further. Then, think about adding elements whose sole purpose is to create repetition like a distinctive font, a numbered list, page numbers, etc. When using repetition, avoid repeating the element so much that it becomes annoying or overwhelming. Be conscious of the value of contrast.
Alignment: Nothing about your design should be arbitrary. Every element should have some visual connection to another element on the page. This creates a clean, sophisticated look. The basic purpose of alignment is to unify and organize the page. You can get alignment by being conscious of where you place elements. Always find something else on the page to align with, even if the two objects are physically far away from each other. When using alignment, avoid using more than one text alignment on the page (don’t center some text and right-align other text for example) and use centered alignment consciously but not by default.
Proximity: Items relating to each other should be grouped close together. When items are placed in close proximity to each other, they become one visual unit rather than several separate units. This helps organize information, reduce clutter, and gives the reader a clear structure. On a page (as in life), physical closeness implies a relationship. The basic purpose of proximity is to organize information. You can get proximity by counting the number of visual elements on the page by counting the number of times your eye stops. If there are more than three to five items on the page, think about which separate items can be grouped together into closer proximity to become one visual unit. When you work with proximity, try to avoid having too many separate elements on the page, sticking things in the corners and in the middle, leaving equal amounts of white space between elements unless each group is part of a subset, confusing readers by creating headlines, subheadings, captions, or graphics that are not clear, and creating relationships with elements that do not belong together