At the heart of everything, from the digital to physical world, is design. Often times and especially in tech, design is oversimplified to describe the appearance of something. This oversimplification can lead to great looking products, with terrible performance or execution. A strong designer recognizes that there is more to design than just the appearances. A physical product, for example, has characteristics of other senses: the way it feels, sounds, and even smells are all relevant to the overall experience of the product. While it is impossible to identify all of the elements involved in the design of a myriad of products, we can share a foundation of knowledge that is applicable to nearly every product whether digital or analog. Consider mastering and memorizing the following over time: Balance, Space, Contrast, Repetition, Alignment, Proximity. A great way to memorize these is to play off the acronym: Be SCRAPy.
These six principles are important to absolutely every product. There are many more principles involved as you distinguish between digital and physical products. As a starting point, however, these are the core principles that every Unicorn should master.