I think this is a challenge that a lot of startups encounter. I've certainly encountered it so far. I think the breakthrough for me was when my dad (good 'ol parents) asked me to describe what I wanted to do in one sentence. Once I did, it became clear how to best focus on what I was trying to accomplish, who I wanted to reach, and how I wanted them to benefit. Sometimes giving yourself some solid guidelines will free you more than anything else. Above all I find that you have to maintain focus. As an entrepreneur I find that you will pick up on many problems that can be solved, and many ways to do so. You have to pick the most important problem to solve, and the way that will solve it the greatest amount is the first one to pursue. My thoughts, from someone that is still learning a lot...