I did not have a clear understanding of culture when I started my company. I was winging it but it worked out well. Perhaps intuiting that I would need to work closely with these people I hired people with a similar mindset and traits. Perhaps a little quirky, but technically solid and a personality that showed up stronger in person than on paper. None of us would ace an interview with an HR person but we had gifts and heart. Over time we had some blow-ups but we also had some good times. My core takeaway was that it was a core culture that kept us together. Sure as heck it wasn't the money because the money was very lean initially. But we stuck together. This was very important.
No startup can afford churn in the early days. So much is invested in 1-1 communications when we're flying by the seat of our pants. Time spent on-boarding, training is time not spent selling and building. So it's important you set the bar and the tempo from the onset. People who get in the groove have a multiplier effect on productivity. The energy must be apparent in every hiring decision and every interaction. And the founder has to make it happen. But there has to be a core authenticity in every interaction. The authenticity is what attracts other people to you and keeps them around. This does not start and end with the recruitment. If a founder is not authentic the mask slips in the impromptu conversations in the hallway. It leaves the other person with a sense of unease. How much do I really trust this person?
But how to build a culture? In the early days culture is an extension of your personality. If you can communicate this well you will get supremely talented people to work with you; even if you don't have the biggest payroll. Look at it this way, the person who interviews with you is likely interviewing with three other companies that week. Each startup will sell the vision as changing the world and becoming the next unicorn. The only way you can excite this one talented person to work with you is through personal affinity. That's the cultural foundation of your company. If there is a cultural alignment it isn't hard work to come into work every day.
But it's absolutely important for the founder to have the self- awareness on who he/she is at the core. Because that core has to be mirrored in the mission and values.