Best designer I've ever met in person, and an expert on mobile-first, tells us the common pitfalls.

Focus on where the action is:

We can no longer just worry about how to fit more controls on a small screen. Now, we have to focus onwhere the action is — on people’s primary flow through an app.

Think of that flow as a speeding freight train. Outside of Hollywood blockbusters, getting in the way of a train usually doesn’t end well. It takes a lot of effort to shift the course of something with that much momentum. So instead of trying to divert people’s attention from their primary task, mobile designers should just hop on board and use the train’s momentum towards their — and their users’ — goals.