Ten Experiments to Test Your Startup Hypothesis – David Teten

The first point "Blog publicly about what you're doing" is one of my favorites. Being open about what you are doing allows you to get so much feedback as well as giving you greater distribution for later projects.

This method is even more helpful if you are starting a company which founders & startup community members will be your early adopters. Writing about your experiences will give users that much more of a connection to you and your brand.