Developing fewer features allows you to conserve development resources and spend more time refining those features that users really need. Fewer features mean fewer things to confuse users, less risk of user errors, less description and documentation, and therefore simpler Help content. Removing any one feature automatically increases the usability of the remaining ones.

A general principle for all user interface design is to go through all of your design elements and remove them one at a time.

Good information architecture makes users less alienated and suppressed by technology. It simultaneously increases human satisfaction and your company's profits. Very few jobs allow you to do both at the same time, so enjoy.

The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

Consistency is one of the most powerful usability principles: when things always behave the same, users don't have to worry about what will happen. Instead, they know what will happen based on earlier experience.

Users are not designers.

In the attention economy, anyone trying to connect with an audience must treat the user's time as the ultimate resource.