This is an intyeresting article which is unlike anything I've seen so far. Basically what it says is - don't be creative. It's useless. Instead, use other success stories as a reference and:

  1. Build on the shoulders of giants - use the design patterns of the most popular apps. Users are used to them.
  2. Each UI should have a goal.
  3. Group together elements that you love.
  4. Test these designs in Wireframes.
  5. These your desgins on real people.

Full article: