I used Steve Blank's formula he described in "The Startup Owner's Manual". Steve is a legend and the process works. I spent 12 months working on a variety of startup ideas, testing them in the market, pivoting and moving on to the next one. Eventually we found one that got traction (paying customers). Two years later, we just closed $13M in series A funding and have dozens of happy customers.

http://markets.businessinsider.com/news/stocks/Leading-Busin...