While many people think it’s just something you get, or you don’t pay that much attention to, culture is really a foundation or building block for your company.
If you don’t have a good company culture, then nothing else can succeed.

All the great organizations in the world, all the great sports teams you think about, the military, the SAS.
They succeed in part because they have a fantastic culture that everyone buys into.
So, if you accept the premise, that culture is a building block, a foundation of having a great company, then what makes a great culture.
Treat culture as a building block, not an afterthought. Decide what you stand for, say it often, and hire and lead in line with it. Small habits each week do more than a big launch. For more on this, have a read of how team culture drives growth and profitability. There is also a general page on organizational culture on Wikipedia.