Build more housing in the major metropolitan areas to meet demand is a fantastic start to it all. Look at how much is built in the big desirable cities. It's not enough, which is driving up prices to absurd levels (looking at you specifically San Francisco in particular). Decommodify housing where possible and take away it's ability to devolve into strictly a monetary investment vehicle.

>Better cultural opportunities outside major metropolitan areas?

There is so much historical inertia behind the cultural opportunities in many places that this one will be hard to do and take an inordinate amount of time I think.