I love this post on organisational culture (building on from the classic “choose boring technology”). This bit especially:

The best informal culture is almost always bottoms up. But managers, execs, HR/People teams, etc can encourage informal culture. One of the most powerful things you can do is just participate. Show up for drinks, play the board games, keep the puns rolling, get silly with your team! Your participation gives people permission and shows that you value their creative cultural labor at work.