Hi Op,
Do you have people and problem solving skills?
You can try managing rental property as a co-host, and take 3-5%, that is a great side job but you have to deal with people.
Are you good with organization and is handy around the house?
Since you mentioned yard work, I am thinking you are willing to do hard work.
For example: I am looking for someone to help sort my garage, basement and many area of my home. Your help will improve life, what would you charge for each room ($500 per room or $1200 for the project?). Also, many parents are looking to have a system in place for the long run, so having shelves or boxes can help but it's hard for them to start...
Something like this will bring you long term revenue, but you have to enjoy doing these type of work, otherwise, it is just better to get a 2nd job (evening or weekend PT job), right?
https://www.themodelhm.com/home-organizing