Great list. I have another to add that’s almost as easy to do as going for a walk! Provide a litter cleanup service outside commercial properties for property management companies. The work is done on foot using simple hand tools. I started this service in 1981 as a side hustle and quickly grew it into a lucrative full-time business that I still operate. I share my experience with others in my book, Cleanlots, as well as offer free support.