[stevofolife]

Look at success stories. What did Kickstarter do? What did TaskRabbit do? What did company XYZ who is similar to your business do?

Study your competitors.

[mattcantstop]

And the failures as well to avoid survivorship bias. Sahil wrote a great book called "The Minimalist Entrepreneur" that goes into a lot of depth about finding customers. Also, Stripe Press has a book called Get Together that covers how to create community as well. I would recommend both books.