Straight up, get politically involved in your community
It might sound silly or inconsequential, but it will have an impact. Even a small impact is better than no impact.
You want a more pedestrian focused city plan to happen? More parks? More multi-family housing? Better bus lines? Get involved, talk to your city council, get your friends involved.
It might sound small, but all change starts small.
Edit: Hell a friend of mine was able to get enough people in his HOA together to get them to start looking into adding some more people focused stuff to their little community. Like adding a couple bike racks to the park in their neighborhood and blending the curbs in a bunch of places.