Team building week: know their qualities
It is quite easy to assume that you know your team well. Actually, just like you, they are always looking for new things to try, new routes to explore and new techniques they want to explore. Building a better team means that you (and the rest of the team) keep in the loop about what everyone is doing, so everyone can make sure to get the right people involved if they hit a roadblock.
Example: I recently learned that one of the guys in my team is interested in 3d modeling and is doing this in his spare time. This is not something that is applicable right now, but it might be in the future. When that moment happens, it is good to have a good map of the qualities and skills in your team. One on ones are a great moment to learn about this stuff, by asking if there are any interesting outside-of-work stuff they are working on.