CRAP Principles
Contrast: Elements like type, color, size, line thickness, shape, space, etc. are not similar to each other, they will need to be changed.
Repetition: Repeat certain elements like colors, shapes, textures, spatial relationships, line thickness, fonts, sizes, and graphic concepts to keep things organized.
Alignment: Place things in line with each other, and try not to make them look too disorganized. It is more appealing to the eye if elements look neat and advanced.
Proximity: Items that relate to each other should be grouped closely together, so that the information is neatly organized. When information is grouped together it is easier for the reader so find what they need.