Here is a short list, but there are many more things which come only from experience and feel interviewing. This is why it is best to have at least 15 years' professional experience before starting a company.

1. Hire the best people you can afford, using stock options to find the ones that really care about the mission and will take submarket salaries to be on the mission.
2. You need 3 key founders: Operator, visionary and sales/marketing head. All with 15 years' experience and long-term commitment. Ideally, willing to put in some cash too.
3. CEO should screen first 100+ employees personally to set the culture well. Maintain a flat organization as long as possible, often until you have 15 employees, to avoid politics and have strong communications. All startups are a learning experience and need to adjust and pivot.
4. We call the ideal culture a Darwinian Meritocracy(TM). It evolves with all inside and outside factors (agile, reorgs) and rewards results, honesty, shared values, hard work...