Write: "Tresspassers will be shot, survivors will be shot again". And paint fake body count over 5 next to it. Add fake and visible claymores on frontyard, old issues of "Guns&Ammo" on your porch.
You can also write fake letter to your fake roomates:
"Hey, Billy Ray. Went to pick up Randy from prison. Be back in a jiffy. Brutal and Grinder were aggresive as *****, we should put them to them dog ring fights again. Anyway I closed them both inside, so watch out, ok? Did you remember to buy beer and extra ammo for rifles?
C'ya
Raymond"
But seriously: you can't have too much security at your home. When we lived in house we had motion detector connected lights and anti-burglar shutters. If you set the reflectors right it won't be too much of a hassle for neighbours. While they may not pay that much attention after some time, the burglars will know that if they approach home there might be witnesses. Professional shutters work nice too, of course they can be breached but it takes time and it's visible. Both these things can help you scare off thieves.