Simply put, our culture is how we do things around here and it's important that leaders own, drive, and demonstrate this. We should set the tone for our teams. This will particularly help in terms of team interaction and practice alignment. 

We should take the opportunity to share our values and principles as often as possible, and not just by posting them in a location in which our people are likely to see them every day, but actually by referring to them and discussing how they affect our decision making.

Just as with purpose, it's likely that there will be company-wide values and principles that will trickle down. Our job is to highlight how they fit with our group's culture, maybe adjusting them to fit our context/put them in our own voice, and using them as a foundation to add our own, group-specific rules of conduct.

These are simple statements, easy to remember, and not so many that we can't remember all of them. One format is to set value and principle statements that follow the two headlines "Who we are" and "How we work":

Who we are:

• Trust and respect each other
• Honest and authentic
• Learn and improve
• Easy to deal with

How we work:

• Build user-focussed products
• Collaborate with everyone
• Try things and fail fast
• Consider the long-term value
• Have fun

Discuss these with your team at regular intervals and revise them if necessary. Simple things like making our values and principles part of our job descriptions create the expectation that our people need to work on the cultural aspects of their role as much as any other.