I know that I am late for the party.
I agree with CarolineScott, to add as you go.
I try to do a bit at a time so I don't become overwhelmed.
I started by installing raised beds Hugelkultur/lasagna beds.
I stopped using any store bought amendments, fertilizers or bagged materials for my annual beds and perennial beds, everything must be sourced locally. I make my own fertilizers.
(I need to clarify this, I do use 10-10-10 on my potted plants and aquaponic plants along with tomato spikes for my pond lilies)
The last few years I have been no till and do in situ composting.
I Started harvesting/diverting rain water, installed a mini rain garden, started a native plant butterfly/hummingbird garden for pollinators.
I have recorded my last few years of Urban Gardening and how I have slowly been trying to convert as much as possible to permaculture philosophies (the best I can anyhow) and I can go on and on with a ton of new things I have done but will hold off to see if there is an interest in resurrecting this thread.