1. Jakob's Law of the Internet User Experience

Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know. (See 2-minute video discussing Jakob's Law in further depth.)

This Law is not even a future trend since it has been ruling the Web for several years. It has long been true that websites do more business the more standardized their design is. Think Yahoo and Amazon. Think "shopping cart" and the silly little icon. Think blue text links.