Don’t expect to get it right the first time. Let the app grow and speak to you. Let it morph and evolve. With web-based software there’s no need to ship perfection. Design screens, use them, analyze them, and then start over again.
You don’t need to aim for perfection on the first try if you know it’s just going to be done again later anyway. Knowing that you’re going to revisit issues is a great motivator to just get ideas out there to see if they’ll fly.
You can’t get a rocket to the moon just by aiming it. You also have to give yourself the ability to course correct. And when we look around at the landscape of really big successes, very often what we see is that the course correction turned out to be more important than the initial direction. http://www.mckinsey.com/insights/high_tech_telecoms_internet/the_disruptive_power_of_collaboration_an_interview_with_clay_shirky