Cookie permissions need to follow the law and strike the balance between respecting user privacy and being user-friendly.

Whitespace is an effective principle to achieve a balanced design, making it easier for your users to scan and read. Consider using a consistent spacing system and the proximity principle to achieve a balanced use of whitespace.

While completing a form isn’t usually a particularly fun task for a user, it is often a necessary step of a process. For example, a user might be asked to fill out a short form with payment details to buy an item or they might have to complete a form as part of a job application.

Mobile devices … seamlessly bridge the gap between the physical and digital realms, making information and services readily accessible to their users at all times. Mobile design is a balancing act between functionality and simplicity, in which the goal is to create a user experience that is easy to use for all.

In a distracted environment, the best form of smartphone interaction is a high-speed, easy-to-use one. Luke calls the typical mobile usage a "one thumb, one eyeball" experience, since the highly distracted environment causes most mobile users to engage in one-handed use with short spans of partial attention.