Dave McClure, founder of seed and incubator fund 500 Startups, which provides betwen $10,000 to $250,000 in seed capital, is a pretty well-known angel investor. Dave has invested in more than 100 startups, such as Mint (acquired by Intuit), Crowdflower, Sendgrid, Simply Hired, SlideShare and Twilio, to name a few.

As you can imagine, Dave's spent enough time with entrepreneurs to know what kind of advice they need.

Here's his three pieces of advice:

Be revenue focused- transation, and not we’ll-figure-it-out-later model.

Be user focused (solving problems that exist)

Be metrics focused and focus on improving conversion metrics.