Make frequent trips to the shooting range. Or at least, act like it. When you see them outside; walk outside with your guns, ammo, stuff, and load them into your car. Don't brandish your firearms, just act nonchalant as if you were heading to the range. Drive off. Show back up in a few hours. Unload your car with holes in paper targets. Hell, make them them all bullseye's for shits and giggles.

They aren't going to rob you when you are home. And chances are they won't rob you knowing that you could come home, and you are well experienced with firearms.

I remember hearing that 80% of home break-ins are by people you know, or who have been in your house before. Letting everyone know that I am well armed seems to be working for me.