Your Outline Is Your To-Do List
As you move on to sketches, wireframes, mockups, and prototypes, refer to your outlines. They serve as checklists for all of the things you need to consider. Did you sketch this feature? Does your wireframe account for that problem? Go through your outlines one item at a time, and make sure you haven’t forgotten anything. Developing an app is a huge project with a squillion tiny parts, and you’re sure to find things you need to add or change at the last minute. But being thorough up front will help you avoid the worst of it.