The best advice I heard for non zero-to-one folks was to watch for Series B rounds where multiple top tier venture firms participated, for example Sequoia + Lig

The best advice I heard for non zero-to-one folks was to watch for Series B rounds where multiple top tier venture firms participated, for example Sequoia + Lightspeed or Benchmark + Accel. This was back around 2012 so the economics could have shifted, less so the firms although there's been some movement. Series B @ $150-$250m valuation seems to be the place where PMF is (usually, not always) de-risked but the company still has room to grow 10-20x (in a good tech market).