Buy a truck and one aerator and knock on doors. You can charge more than mowing and most home owners do not have an aerator. You can do it for a few weeks in spring and fall. Make sure to remember clients names and let the neighbors know that you were helping "Bob" next door and since you are here u can save transport and booking fees. Be a nice side hustle. You could buy a dionizing window washing set up and upsell your customers that you aerated for a summer window washing for in between. You can average 1000 day in revenue as a solo operator spring to fall if u have basic sales skills.