“Design principles, when we chose them effectively, become the driving rationale behind our future design decisions.” Jared Spool

9 basic principles of design, Balance, Alignment, Emphasis, Proportion, Movement, Pattern, Contrast, Unity & Perspective.
Each principle has a fight of it's own when a designer is drafting a concept.
Apart from the Main 9, here are the NEW Design Principles which are mostly used in context to design.

1. Design For Everyone
2. People Over Pixels
3. One Brand To Rule Them All
4. The Details Are The Design
5. Design is A Shared Responsibility
6. Creativity Fosters Community