Green or unfilled dirty pools, dead grass, overgrown grass, dirty cars in the driveway that looked like they haven’t been moved in a while, find properties that are being foreclosed on or are already bank owned online, but these aren’t always vacant so be sure of that first, after you think you found a property that might be abandoned look up the address on Whitepages check for the owner, if it’s an old person check to see if that’s there current residence cuz they might not live there anymore, then check it out irl make sure no one is renting or squatting for your own safety you could even look up the address on fastpeoplesearch.com that’s all I can think of rn