Various design methodologies can be employed when doing visual design - for example, 'brutal' or 'post-punk'. Different companies have their own design languages in a broad sense. For example, Google is a large propogator of [Material Design](https://material.io) in which design elements are made to look like real materials with the same flow and shadow effects.
Visual Design deals with how applications looks to the user as well as how it feels. It can be seen as the digital equivalent of graphic design. And as such, visual design should also strive to follow Dieter Rams' well-known principles of good design.
- [10 timeless commandments for good design](https://www.interaction-design.org/literature/article/dieter-rams-10-timeless-commandments-for-good-design)