Source: https://www.usability.gov/what-and-why/visual-design.html
In truth, every principle and element overlaps.
There's actually a lot more to design knowledge than what you see above, based on what discipline(s) you come from and who teaches you, as you can see below. However, at three o'clock in the morning—or right now as you struggle—when you're on deadline and something just doesn't seem to work, revisiting the CRAP principles is all you need to do to get up and running again.
Elements of design
Point
Line
Color
Shape
Size
Scale
Form
Pattern
Space
Texture
Typography
Principles of design
Contrast
Repetition
Alignment
Proximity
Unity
Harmony
Balance
Position
Rhythm
Structure
Direction
Density
Emphasis
Similarity
Hierarchy
Dominance
Gestalt