My current team is repeatedly cited as one of the most fun and open teams in the org by many (both from inside and sidelines), and I can suggest some things that seem to work:
1. Psychological safety and honesty is subtle and contagious - if one person opens up and always makes a point in identifying their own mistakes (perhaps going out of the way at times) others feel empowered to do so as well. This ideally needs to be done by the senior most members of the team to start.
2. Make it a point to never (even subtly) blame individuals in even the slightest of public settings for any mistakes. Use 1-1s to do that and encourage the same throughout the team
3. Safety is contagious but the opposite is true as well - bad influences in the form of PMs out of sync with team culture should be avoided as quickly as possible.
4. Everyone should always feel like the team has their back in any external surface (either their managers, the customer success team, the product management team, etc) - any slight or suggestion that an individual might not have done something optimally should be backed by honest support from the remainder of the team. Not lying or defending bad actions but just assuring that the team will work together to rectify any problem.
5. Make it a point to publicly acknowledge any good contribution by any team member.
6. In any public channel even within the team, all engineers are treated as if they are equally senior.
7. Display and inspire a sense of responsibility towards the product, not because you owe it to your company, but you owe it to the customers, to your teammates, and other teams in the org that will have to make up for any mistakes we do. Again not by working overtime (not more than once or twice of course).
8. Fully acknowledge that no one should work "too hard" (read: more than 9-5 on most days). If one engineer does because they have no life, make sure everyone knows that's not anyone else's problem (and make sure that this extra-work engineer doesn't cause trouble via bad code or unrealistic expectations).
9. Be brutally honest to each other in 1-1s, and try to use the same techniques as above to do so.
10. Never hold back feedback from each other that you feel obligated to give in peer reviews eventually anyway. Give it to them (privately) as soon as possible.
1. Psychological safety and honesty is subtle and contagious - if one person opens up and always makes a point in identifying their own mistakes (perhaps going out of the way at times) others feel empowered to do so as well. This ideally needs to be done by the senior most members of the team to start.
2. Make it a point to never (even subtly) blame individuals in even the slightest of public settings for any mistakes. Use 1-1s to do that and encourage the same throughout the team
3. Safety is contagious but the opposite is true as well - bad influences in the form of PMs out of sync with team culture should be avoided as quickly as possible.
4. Everyone should always feel like the team has their back in any external surface (either their managers, the customer success team, the product management team, etc) - any slight or suggestion that an individual might not have done something optimally should be backed by honest support from the remainder of the team. Not lying or defending bad actions but just assuring that the team will work together to rectify any problem.
5. Make it a point to publicly acknowledge any good contribution by any team member.
6. In any public channel even within the team, all engineers are treated as if they are equally senior.
7. Display and inspire a sense of responsibility towards the product, not because you owe it to your company, but you owe it to the customers, to your teammates, and other teams in the org that will have to make up for any mistakes we do. Again not by working overtime (not more than once or twice of course).
8. Fully acknowledge that no one should work "too hard" (read: more than 9-5 on most days). If one engineer does because they have no life, make sure everyone knows that's not anyone else's problem (and make sure that this extra-work engineer doesn't cause trouble via bad code or unrealistic expectations).
9. Be brutally honest to each other in 1-1s, and try to use the same techniques as above to do so.
10. Never hold back feedback from each other that you feel obligated to give in peer reviews eventually anyway. Give it to them (privately) as soon as possible.