Above and beyond any specific policy areas such as coding standards, seniority mixes and son on, the biggest and most important thing to manage is the overall software development culture. If you can energise the culture, and inspire people to believe in the mission, to fight for it like their own flesh and blood, as well as to honour each other's diversity of perspectives, you will achieve far more than by drawing policy lines in the sand. Keep it fun. Make the crew feel special. Give them a feeling that their futures are within their control.
This said, I would also recommend frequent peer code reviews - this will inspire better work, knowing that people are accountable to their peers. Also, be on the lookout for single-sourcing, and fight it off like the plague, even if it has a productivity cost. Yes, Natalie is brilliant with the middleware. But what if she gets hit by a bus, or leaves to have a kid? Defend in advance by ensuring there are others who can instantly step in and take over from her.
Again - an energised culture with a strong team spirit - a deep and powerful soul - will optimise the workplace far better than any arbitrary standards.