In the midst of a transition like the one our society is presently beginning, growing organic food locally is one of the most sensible things we can do. Being the kind of person who likes to do stuff that is sensible, I decided to start this process in the little yard of the rental property where I live. As you can see, it is the only patch of yard in a sea of apartment buildings and pavement.
Like many such properties, this had more or less been treated like a garbage dump for decades. The "soil" consisted of gravel, broken glass, construction waste, sand, and dog poop. So I started with compost (after coming up with a plan and getting formal approval to go ahead with the project).
I built a little box from scrap wood, found a suitable indoor collection can, and labeled the top of the can with some simple instructions for the half-dozen fellow renters I share space with.
By picking up food waste from local businesses and yard waste from nearby alleys, and combining this with a couple of yards of donated-by-a-good-friend farmpost, I was in business.
Using permaculture techniques, simple hand tools, and scavenged materials, I got the space turned into a healthy and productive outdoor place. In another few years, it will be a maintenance-free and food rich micro habitat.
It isn't much, obviously, but it is something. Which is more than most people do towards fixing the broken world we inherited.