Design for regular, blank, and error states

For each screen, you need to consider three possible states:

• Regular
  The screen people see when everything’s working fine and your app is flush with data.
• Blank
  The screen people see when using the app for the first time, before data is entered.
• Error
  The screen people see when something goes wrong.

The regular state is a no-brainer. This is the screen where you’ll spend most of your time. But don’t forget to invest time on the other states too (see the following essays for more on this).