Boarded windows (you can actually find specifics on what works) and make sure everything is closed up tight.
I got a few signs from a security company and placed on the doors and lawn. Also do the usual, maintain your lawn, close the blinds put timer on lights, etc. Make your home look lived in.
Get a renter for it, allow at rusted person to house sit, install an alarm system with cameras.
Vacant for how long? Years? Get a renter to live in it.
