I also live in the suburbs. I have a very small garden where I initially took the stone coverage away, added some compost to mostly sand, and then planted out a number of species from a local permahero. Now it mostly lives by itself, with a lot of cool insects in it. I also have a small raised bed where I put some wood, charcoal and compost, and now plant stuff with varying success. But the birds love the living soil. Am dreaming of buying more land one day.
Urban forestry sounds interesting, will have to check that out! The Permaculture Podcast by Scott Mann has a number of interesting episodes on differing subjects - definitely recommended from here.