Turn the water, gas, and electricity off. Park a car under the attic access to make it inaccessible. Lock the crawl space door. Clutter the home with stuff so thoroughly that all the windows and outlets are inaccessible. That would be a good start.
Don’t forget to paint the basement walls and any ceiling stains. And lay out rugs cover any floor cracks or stains. Strategically place all your storage items in front of the electrical panel. And fill all areas under sinks with all the junk you can find.
Joe, you forgot: Place the wrong key in the lock box, and transpose 2 of the numbers. Or better yet, place the key to the BACK door, in the lock box on the FRONT door, to make things easier.
And most important of all, make sure your Agent sends us to 123 Walnut Street, instead of 123 Walnut Avenue.